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Enclosure Cooling
You need to cool down
Heat inside an enclosure can decrease the life expectancy of controlling units such as your PLC, HMI, AC drives and other items.
Excessive heat can cause nuisance faults from your electrical and electronic components: for example, overloads tripping unexpectedly.
Heat will also change the expected performance of circuit breakers and fuses, which can cause whole systems to shut down
unexpectedly. So, if you have any electronic equipment or other heat sensitive devices, you may need cooling.
What causes all that heat?
There are basically two sources that can cause the enclosure’s internal temperature to rise above the ratings of the control equipment.
Internal Sources External Sources
The same items that can be damaged by heat may also be the Other sources of heat that can cause the internal temperature of
source of the heat. These include items such as: your enclosure to rise above a desired level involve the external
• Power supplies Servos environment. These include items such as:
• AC Drives/inverters Soft starters • Industrial ovens
• Transformers PLC systems • Solar heat gain
• Communication products HMI systems • Foundry equipment
• Battery back-up systems • Blast furnaces

Get the heat out Natural Convection Cooling HOT

How do you get the heat out of your enclosure and away from those critical
components? There are several basic cooling methods available, depending on
the cooling requirements and the enclosure environment.
Radiation and Natural Convection Cooling
If the ambient temperature outside the enclosure is cooler than the inside of the
enclosure, some heat will be radiated into the atmosphere from the surface of
the enclosure. In environments where dust and water intrusion is not a concern,
louvers can be added to allow outside air to flow through the enclosure via
natural convection - the movement of air due to it’s expansion (reduced density)
when it’s heated and contraction (increased density) when it cools.
On a large scale, natural convection can be a powerful force - it’s one of the
primary drivers of our weather. But on the scale of an electrical enclosure, its
cooling capacity is very limited. For larger heat loads, a more powerful cooling
system may be needed. HOT

Since they create openings in the enclosure, louvers are typically limited to Forced Convection Cooling
NEMA 1 and/or NEMA 3R applications. However, some louvers have optional
filters that can be added to maintain NEMA 12 protection.
Forced Convection Cooling
The next step up from natural convection is forced convection cooling. The
basic cooling mechanism is the same: cooler air from outside the enclosure
passes through the enclosure to remove the heat. The difference is that the air
is mechanically forced through the enclosure by a filter fan. The fan produces
higher air flow rates than natural convection, which in turn increases the amount
COLD
of heat removed.
HOT
As with natural convection cooling, the ambient air temperature must be lower
than the desired enclosure temperature for forced convection to be effective.
A typical forced convection system consists of a fan and a grille, with a filter on
the intake device and either a filter or louvers on the exhaust device. The filters
and louvers allow the enclosure to maintain NEMA 12 protection. In NEMA 4 or
NEMA 4X environments, hoods can be added to both the fan and the grille to
prevent the ingress of water.

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Enclosure Cooling
Closed Loop Cooling
If the environment is harsh, with heavy dust and debris or the presence of airborne Air Conditioners & Heat Exchangers
chemicals, or there are wash-down requirements, the cooling system must be able
to keep the ambient air separate from the air inside the enclosure.
Closed loop systems, which include heat exchangers and air conditioners, circulate
the internal air and ambient air through separate chambers connected by a COLD
refrigeration system that transfers heat from the internal air stream to the external
air stream. Heat exchangers and air conditioners are both closed loop cooling
systems. The primary difference in the two is the refrigeration system.
The refrigeration system in a heat exchanger is a set of sealed tubes of alcohol.
Heat absorbed from the internal enclosure air boils the liquid alcohol at the
bottom of the tube, causing it to rise to the top. The heat is then rejected to the
cooler ambient air stream, causing the alcohol to condense back to a liquid and fall
to the bottom. HOT

Heat exchangers are very efficient because the refrigeration system has no moving
parts - the only moving parts are the two fans. But for the heat to transfer through
the system, the ambient air must be colder than the air inside the enclosure, just as
it must be for filter fans.
Enclosure air conditioners function in the same manner as a residential or
automotive air conditioner, with refrigeration loop powered by a compressor. The
refrigerant absorbs heat from the internal air at the evaporator coil and rejects it
to the ambient air at the condenser coil. Unlike heat exchangers, they can provide
cooling even if the ambient temperature is higher than the enclosure temperature.
They can also be scaled to handle larger heat loads than any other cooling system.
Enclosure air conditioners are available for NEMA 12, NEMA 4 and
NEMA 4X applications.
Vortex Coolers
Vortex coolers create a stream of extremely cold air from a supply of filtered Vortex Cooling Compressed

compressed air. The cold air is injected into the enclosure, displacing warm air Air In

which is exhausted back through the vortex cooler. While not a closed-loop
Internal
Air Out
Relief Valves to

system, they can be used in the same harsh environments since the cold air
Vent Hot Air

injected into the enclosure is filtered air from a compressed air system, not
ambient air. Vortex coolers can also be used where the ambient temperature is
Internal Solenoid
Air In Valve

higher than the enclosure temperature. Internal

Filter/
Regulator
Air In

Since vortex coolers prevent the ingress of ambient air or sprayed water and are Cold End Adjustable

made from corrosion-resistant materials, they can be used on NEMA 4X enclosures

Muffler Thermostat

in harsh, wash-down, and/or corrosive environments.

Clean Cold
Air Inside

Vortex coolers are commonly used in lieu of a small or medium enclosure air
conditioner in applications where there isn’t adequate space to mount an air
conditioner, provided there is an adequate supply of compressed air.
Thermoelectric Coolers
Another alternative to a conventional air conditioner is a thermoelectric cooler,
which is sometimes referred to as a Peltier cooler. They function in a manner
similar to an air conditioner or heat exchanger, with fans inside and outside the
enclosure, but with a thermoelectric unit replacing the fluid-based
refrigeration system. Thermoelectric Cooling

The thermoelectric units consist of an array of semiconductors sandwiched Ambient

between two ceramic plates. When a DC current is applied to the semiconductor Air Out
Internal

array, heat is driven from one plate to the other, creating a cold side and a warm
Air Out

side. This is known as the Peltier Effect. Fans circulate air across each of the plates,
allowing the cold plate to absorb heat from the enclosure and the warm plate to Ambient Internal

reject it to the ambient air.

Air In Air In

Like vortex coolers, thermoelectric coolers can be used with NEMA 4X enclosures Internal

in harsh, wash-down, and corrosive environments, and where the ambient

Air Out

temperature exceeds the enclosure temperature.

Thermoelectric coolers are an alternative to air conditioners in small cooling
capacity applications where there isn’t adequate space for an air conditioner. Ambient
Air Out

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Selecting an Enclosure Cooling Device

Cooling Basics
To select the proper cooling device for your enclosure, you need to determine how much heat the device must remove from the
enclosure to maintain the desired internal temperature, which is the sum of two component heat loads: Internal Heat Load and Heat
Transfer Load.

Internal Heat Load (Qi)

The sum of all heat generated by the components within the enclosure. This can be calculated by adding the maximum heat output for
each device installed in the enclosure (the worst-case conditions for the enclosure). The maximum heat output is typically specified in
watts in the manufacturer’s documentation. If it is not, contact the manufacturer to request the heat output or for guidance on how to
measure or calculate it.

Heat Transfer Load (Qx)

The heat gained (positive heat transfer) or lost (negative heat transfer) through the enclosure exterior surface with the surrounding
ambient air. This can be calculated with the following formula:
QX = kAΔT (BTU/h), where:
k = heat transfer coefficient (BTU/(h·ft2·°F))
The heat transfer coefficient is a measure of how easily an enclosure conducts heat from the internal air to the external air,
which varies with the enclosure material. Suggested values for various enclosure materials are provided below:

Enclosure Material k, BTU/(h·ft2·°F)

Painted carbon steel 0.97
Stainless steel 0.83
Aluminum 2.1
Polycarbonate, fiberglass, PVC, ABS 0.62

A = exposed enclosure surface area (ft2)

The total surface area of a rectangular enclosure is:
A = 2HW + 2HD + 2WD, where:
H = height
W = width
D = depth
But it’s important to properly account for any surfaces that are against walls or floors, as those surfaces will absorb/reject
heat from adjacent surfaces at a different rate (that is, have a different k value) than the exposed surfaces. Quantifying that
difference is far beyond the scope of this document, but the q value for those surfaces will usually be less than the value for
exposed surfaces. Therefore, the conservative design approach should be to exclude those surfaces when ΔT < 0 and use the
total surface area when ΔT > 0.
The equations for excluding those surfaces in several common situations are listed below.

Wall-mount
A = HW + 2HD + 2WD
(excludes back of the enclosure)
Freestanding enclosure
A = 2HW + 2HD + WD
(excludes the bottom of the enclosure)
Freestanding enclosure against a wall
A = HW + 2HD + WD
(excludes both the bottom and back)
Freestanding enclosure in a corner
A = HW + HD + WD
(excludes the bottom, back, and one side)
Using these formulas as written will produce answers in either in2 or mm2, depending on the enclosure. To convert to ft² use
the appropriate conversion:
1 ft² = 144 in²
1 ft² = 92,900 mm²

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Selecting an Enclosure Cooling Device

ΔT = TA – TE , where TA is maximum ambient air temperature (°F) and TE is maximum allowable enclosure air temperature (°F)
Note that ΔT may be negative if the ambient temperature is less than the enclosure temperature. When this is the case, the
heat transfer load will also be negative, meaning that the ambient air is providing some degree of cooling. Whereas a positive
ΔT indicates that the ambient air is warming the enclosure.
A positive ΔT also indicates that neither a fan nor a heat exchanger is a viable cooling device for this application. Both devices
exchange heat between the interior and exterior of the enclosure. Since heat will always move from the higher temperature
material to the lower temperature, these devices will add heat to the enclosure which will raise the internal air temperature, not
lower it.
The maximum allowable enclosure air temperature will typically be dictated by the maximum operating temperature of the
components inside the enclosure. Be sure to choose the component value with the lowest maximum operating temperature.

Required Cooling Capacity (Qr)

The required cooling capacity (Qr) for an enclosure is simply the sum of the Internal Heat Load and the Heat Transfer Load. However, as
presented these values cannot be simply added since one is typically given in watts and the other in BTU/h. Additionally, fan and heat
exchanger sizing formulas require the total heat load in watts, while the cooling capacities of vortex coolers are generally expressed in
BTU/h. However, the cooling capacities of air conditioners and thermoelectric coolers may be expressed in either unit, or sometimes
both. Apply one of the following conversions to the heat loads to add them:
1 W = 3.41 BTU/h Qr (BTU/h) = Qi x 3.41 (BTU/h)/W + Qx
1 BTU/h = 0.293 W Qr (W) = Qi + Qx x 0.293 W/(BTU/h)

Vortex Cooler Selection

Once the required cooling capacity has been calculated, selection of a vortex cooler is simple – just select a cooler with a nominal
cooling capacity greater than the calculated requirement.

Air Conditioner and Thermoelectric Cooler Selection

Selecting an air conditioner or thermoelectric cooler is more complex because their performance depends on both the ambient
temperature and the enclosure temperature. Generally, more strenuous operating parameters (higher ambient temperature, lower
enclosure air temperature) will reduce the unit’s performance. For this reason, manufacturers publish curves that graphically describe
the unit’s cooling capacity over a range of conditions. Here’s an example:
Enclosure Air Temp
131°F/55°C 122°F/50°C 95°F/35°C 68°F/20°C

Ambient Temperature (°C)

18 24 29 35 41 46 52 57
2800 2051

2400 1758
Cooling Capacity
Cooling Capacity

2000 1465

1600 1172
(Watt)
(BTU)

1200 879

800 586

400 293

0 0
65 75 85 95 105 115 125 135

Ambient Temperature (°F)

As indicated by the red lines, this air conditioner would be able to remove 1000 BTU/H when the ambient temperature is 95°F and
enclosure air temperature is 95°F. If the ambient temperature was only 75°F, the cooling capacity of the unit would increase to
approximately 1105 BTU/H as the lower ambient temperature increases the unit’s condenser’s ability to reject heat to the surrounding
atmosphere. Conversely, at a 95°F ambient temperature and a 68°F enclosure air temperature, the unit’s capacity would be reduced to
approximately 945 BTU/H, as the lower enclosure air temperature would reduce the heat transfer rate between the internal enclosure air
and the unit’s evaporator coils.
To determine if an air conditioner or thermoelectric cooler meets application requirements, simply plot the two maximum temperatures
used in the ΔT calculations and read the corresponding cooling capacity on the y-axis of the chart. If that value exceeds the required
cooling capacity, the air conditioner will be adequate for the application. If not, select a larger capacity unit.

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Selecting an Enclosure Cooling Device

The 95°F/95°F point is typically used as the nominal cooling capacity of the unit. But always keep in mind that any nominal capacity only
represents one set of operating parameters. If those parameters to not match the actual application conditions, the actual performance
of the air conditioner/thermoelectric cooler will be different.

Never rely solely on a nominal cooling capacity when selecting an air conditioner or a thermoelectric cooler! The nominal
capacity is solely intended to provide an approximation to get the user “in the ballpark” of the selection process.

In addition to the required cooling capacity, an air conditioner or thermoelectric cooler should also maintain the NEMA rating of the
enclosure. Ideally, it should also operate on a voltage already available within the enclosure to avoid necessitating a transformer or
power supply.

Air Conditioner Selection Example

A NEMA 12 Wiegmann N12302412 wall-mount enclosure (30 in high x 24 in wide x 12 in deep) contains a GS4-4060 AC drive (60 HP
460V) that has a maximum allowable operating temperature of 104°F and is inside a plant with a maximum ambient air temperature of
115°F.
The GS4-4060 specifications table indicates its maximum Watt Loss to be 1147 W.
Internal heat load:
Qi = 1147 W x 3.413 (BTU/h)/W = 3914 BTU/h
Heat load transfer:
k = 0.97 BTU/(h·ft²·°F)
ΔT = 115°F – 104°F = 11°F (Reminder: ΔT >0 means that fans or heat exchangers will not cool the enclosure!)
A = [2(30 in x 24 in) + 2(30 in x 12 in) + 2(24 in x 12 in)]/144 in²/ft² = 19 ft²
Qx = kAΔT = (0.97 BTU/(h·ft²·°F))(19 ft²)(11°F) = 202 BTU/h
Required cooling capacity:
Qr = Qi + Qx = 3914 BTU/h + 202 BTU/h = 4116 BTU/h
AutomationDirect offers several NEMA 12 460VAC models that meet or exceed 4605 BTU/h at 104°F. The curves for the appropriate
sizes of some of these series are shown below.
Enclosure Air Temp
131°F/55°C 122°F/50°C 95°F/35°C 68°F/20°C Performance curve
SCE-NG5290B120V, SCE-NG5290B230V, SCE-NG5290B460V3
Ambient Temperature (°C)
enclosure air temperature
18 24 29 35 41 46 52 57
8000 2344 131°F/55°C 122°F/50°C 95°F/35°C 68°F/20°C

7000 2051 Performance Graph

7500
Cooling Capacity
Cooling Capacity

6000 1758
6500
(Watt)

Cooling Capacity
(BTU)

5000 1465
5500
(BTU/h)

4000 1172
4500

3000 879 3500

2000 586
2500
65 75 85 95 105 115 125 135 60 70 80 90 100 110 120 130 140
Ambient Temperature (°F) Ambient Temperature (°F)

The NEMA 12 460VAC selection from The NEMA 12 460VAC selection from
this series is SCE-AC5100B460V. this series is SCE-NG5290B460V3.

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Selecting an Enclosure Cooling Device

Heat Exchanger Selection

Heat exchanger capacities also depend on the internal enclosure air temperature and the ambient temperature, but the dependency is a
simple linear relationship between the capacity and ΔT. So rather than graphing the cooling capacity of the heat exchanger, it is simply
expressed in terms of W/°C and compared to the value of -Qr/ΔT.
To convert ΔT from °F to °C, use the conversion 1°C = 1.8°F.

Note that this simplified conversion only works for temperature differences. It does not work for measured temperatures
since 0°F ≠ 0°C. DO NOT apply this conversion directly to the ambient and enclosure air temperatures. Only apply it to ΔT.

Heat Exchanger Selection Example

A NEMA 12 Wiegmann N12302412 wall-mount enclosure (30 in high x 24 in wide x 12 in deep) contains a GS4-4010 AC drive (10 HP
460 volt) that has a maximum allowable operating temperature of 104°F and is in a plant that has a maximum ambient air temperature
of 90°F.
The GS4-4010 specifications table indicates its maximum Watt Loss to be 292 watts.
Internal heat load:
Qi = 292 W
Heat load transfer:
k = 0.97 BTU/(h·ft2·°F)
ΔT = 90°F – 104°F = -14°F (Since ΔT <0, a heat exchanger is a potentially valid cooling device)
ΔT = -14°F/(1.8°F/°C) = -7.8°C
A = [(30 in x 24 in) + 2(30 in x 12 in) + 2(24 in x 12 in)]/144 in2/ft2 = 14 ft²
Qx = kAΔT = (0.97 BTU/(h·ft²·°F))(14 ft²)(-14°F) = -190 BTU/h x 0.293 W/(BTU/h) = -56 W
Required cooling capacity:
Qr = Qi + Qx = 292 W - 56 W = 236 W
-Qr/ΔT = -236 W/-7.8°C = 30 W/°C
A Stratus heat exchanger with a capacity of at least 30 W/°C is needed, such as a TE30-030-17-04.

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Selecting an Enclosure Cooling Device

Fan Selection
A fan cools the enclosure simply by displacing the hot air within the enclosure with cooler air from the outside. Combining the specific
heat of air, the density of air, and various conversion factors into a single coefficient gives a simple equation for correlating a fan’s
required airflow rate to the enclosure’s required cooling capacity:
Fr = -(3.17 CFM·°F/W)Qr / ΔT
Once the fan airflow requirement is determined, fan selection is simply a matter of finding a fan with an airflow greater than the
required airflow. Most applications will require an accompanying grille and one or more filters which will restrict airflow to some degree.
(Exceptions would be a NEMA 1 enclosure or a similar circumstance where an open vent can be used for exhaust/makeup air.) Therefore,
the fan selection should almost always be made based on the “Airflow with Grille and Filters (CFM)” column of the specifications, not the
fan’s Free Airflow.

Fan Selection Example

A NEMA 12 Wiegmann N12302412 wall-mount enclosure (30 in high x 24 in wide x 12 in deep) contains a GS4-2025 AC drive (25 HP
230 volt) that has a maximum allowable operating temperature of 104°F and is in a plant that has a maximum ambient air temperature
of 92°F.
The GS4-2025 specifications table indicates its maximum Watt Loss to be 733 watts.
Internal heat load:
Qi = 733 W
Heat load transfer:
k = 0.97 BTU/(h·ft2·°F)
ΔT = 92°F – 104°F = -12°F (Since ΔT <0, a fan is a potentially valid cooling device)
A = [(30 in x 24 in) + 2(30 in x 12 in) + 2(24 in x 12 in)]/144 in2/ft2 = 14 ft²
Qx = kAΔT = (0.97 BTU/(h·ft²·°F))(12 ft²)(-12°F) = -163 BTU/h x 0.293 W/(BTU/h) = -48 W
Required cooling capacity:
Qr = Qi + Qx = 733 W - 48 W = 685 W
Required air flow:
Fr = -(3.17 CFM·°F/W)(685 W)/-12°F = 181 CFM
Possible 230VAC fan & grille combinations include:
• Stego 018840-40 exhaust fan with 118840-30 grille (187 CFM)
• Fandis FF20A230UE1 intake fan with FF20U grille (209 CFM)
• Stego 018740-30 intake fan with 118740-00 grille (220 CFM)
• Stego 018840-00 exhaust fan with 118840-30 grille (243 CFM)
• Fandis TP19U230B1 roof-mount exhaust fan with FF20U grille (297 CFM)

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Industrial strength cooling options for your

enclosure from AutomationDirect
Heat Exchangers
• For NEMA 4 and 4X enclosures
• Closed loop cooling
• Energy efficient: uses approximately the same power as a filtered
fan system
• 120VAC and 24VDC models available
• UL
• Made in the USA

Air Conditioning Units

• For NEMA 12, 4, 4X type enclosures
• Digital temperature controller
• Active condensate evaporation system
• High unit efficiency
• Tough industrial construction
• Compressor protection system

Enclosure Vortex Coolers Seifert Thermoelectric Cooling Units

• For NEMA 12, 4, 4X type enclosures • For NEMA 4, 4X, and 12 enclosures
• Operates on compressed air • Stainless steel housing
• Stainless steel construction • 170, 340, 510, 680 BTU/H cooling capacity
• No moving parts, no maintenance required • Recessed mounting
• Vortex coolers can be “resized” for changing applications by simply • No maintenance required
replacing the generator inside the cooler. No need to purchase • 24VDC and 120VAC power options
a new unit
• Replacing the vortex generator takes minutes

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Enclosure Air Conditioners

Applications Features
Designed to maintain the temperature • Programmable temperature controller with
inside an electrical enclosure at or visible alarm features in a 0.57 x 0.29in
below a safe level for the enclosed [14.5 x 7.3 mm] panel
equipment, while maintaining a closed • 70˚F to 95˚F (20˚C to 35˚C) temperature
loop environment inside the enclosure to control range
keep out contaminates that can be in the • 50˚F to 125˚F (10˚C to 52˚C) ambient
ambient air. Can be used in environments temperature range
such as steel, food processing, petro- • Pre-wired for external alarm monitoring
chemical, cement, paper/pulp and plastics connections (22 AWG three-conductor cable,
industries, provided there are no corrosive 7 ft (2.3 m) long)
gases or liquids that could damage • Active condensate evaporation system with
internal components. safety overflow
• Protective coated condenser coils on NEMA

Construction 4 and 4X for corrosion resistance

• Thermal expansion valve for maximum
• Free-standing rigid chassis for easy efficiency over wide range of temperatures
installation and maintenance and loads
• All mounting hardware, full-size template • Anti short-cycle compressor protection
and instruction manual included • High and low refrigerant cut-outs with
• Power input terminal block on all models fault indication
• All Type 4 and 4X models come with • Highly energy-efficient compressors
condenser coils coated with an electrically • UL/cUL listed
applied corrosion-resistant coating

TA10-060-26-12 shown

Stratus Air Conditioners General Specifications

Nominal Cooling Operating Inrush Running Recommended Fuse Refrigerant
Part Number SCCR (A) Connection Refrigerant
Capacity Voltage Current (A) Current (A) Size/Time Delay (A) Amount (oz)
TA10-010-16-xx 115VAC/60Hz 14.50 3.44 12 *
1480 BTU/H 4.00
TA10-010-26-xx 230VAC/60Hz 14.00 2.67 7 *
TA20-010-48D-xx 1500 BTU/H 48VDC - 3.50 8 (fast acting) *
6.00
TA20-010-16-xx 1690 BTU/H 115VAC/60Hz 10.10 2.70 5 *
TA10-015-16-xx 115VAC/60Hz 14.60 3.44 12 *
1725 BTU/H 7.75
TA10-015-26-xx 230VAC/60Hz 13.30 2.67 7 *
R134a
TA10-027-16-xx 115VAC/60Hz 10.00 3.20 8 * Spring terminal block
2680 BTU/H
TA10-027-46-xx 460VAC/60Hz 2.64 0.80 2 * 24-8 AWG 13.25
TA20-020-16-xx 115VAC/60Hz 10.63 4.10 5 *
2705 BTU/H
TA20-020-26-xx 230VAC/60Hz 8.84 2.00 4 * 9.75
TA10-033-16-xx 115VAC/60Hz 16.00 4.80 12 *
3300 BTU/H 14.25
TA10-033-46-xx 460VAC/60Hz 16.00 1.30 3 *
TA10-020-26-xx 3585 BTU/H 230VAC/60Hz 13.65 3.07 7 * 9.75
TA10-040-26-xx 4000 BTU/H 230VAC/60Hz 13.41 3.07 6 * 13.25
TA10-050-16-xx 115VAC/60Hz 23.42 7.26 12 * R422d
Spring terminal block
TA10-050-26-xx 4390 BTU/H 230VAC/60Hz 19.15 3.76 10 * 12.50
16-6 AWG
TA10-050-46-xx 460VAC/60Hz 9.18 1.86 5 160kA
TA10-045-16-xx 115VAC/60Hz 32.30 6.82 12 *
4535 BTU/H Spring terminal block 14.00
TA10-045-46-xx 460VAC/60Hz 7.74 1.70 3 * 24-8 AWG R134a
TA10-059-16-xx 5910 BTU/H 115VAC/60Hz 32.30 6.14 12 * 15.00
TA10-060-16-xx 115VAC/60Hz 42.41 7.83 25 * Spring terminal block
TA10-060-26-xx 7580 BTU/H 230VAC/60Hz 21.15 4.80 12 * 16-6 AWG R422d 18.00
TA10-060-46-xx 460VAC/60Hz 10.13 1.80 5 160kA
Note: * Voltage variation no greater than ± 10% from nameplate rating and Frequency variation no greater than ± 3Hz from nameplate rating.

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SoliTherm® Thermoelectric
Coolers thermal innovations

Applications Construction
Thermoelectric elements utilize the Peltier Effect to create a • Recessed mounting (flush-mounting kit sold separately)
temperature difference between the internal and ambient heat • Cooling capacities from 100 to 680 BTU/H [30W to 200W]
sinks, making internal air cooler while dissipating heat into the • Operating Temperature Range: -4°F to 149°F [20°C to 65°C]
external environment. Fans assist the convective heat transfer
• AISI 304 stainless steel housing
from the heat sinks, which are optimized for maximum flow.
• Condensate tray and drain available separately
The Seifert SoliTherm® Peltier thermoelectric coolers can be • Mounting nut torque: 3.3 lb·ft [4.5 Nm]
mounted in nearly every position (except roof mounting) because
• Connection: Terminal block
they don’t have a compressor or any moving parts aside from the
fans. Depending on the application, condensation management • 24 VDC units require thermostat for set-point control
may need to be considered. Seifert SoliTherm thermoelectric
coolers are available as recessed with the internal heat sink
and fan inside the enclosure and the ambient components on
Agency Approvals
the outside. But, frames are available for external mounting. • CE, RoHS
These thermoelectric coolers are resistant to extreme ambient • UL Recognized File number: SA32278
conditions and can operate effectively even in environments that • NEMA 4X
are dusty and oily. They comply with European standards IEC/TC • IP 66
62610-1 and IEC/TC 62610-3, and can be used for both indoor
and outdoor applications.

SoliTherm® Thermoelectric Cooler General Specifications

Max Recommended Fuse
Nominal Power / Operating Inrush Integral
Part Number Cooling Capacity Current Size
Max (W) Voltage Current (A) Thermostat
(A) (A)
3035303 44 - 52 100 BTU/H [30W] 4.0 2.2 5
3050303 58 - 60 170 BTU/H [50W] 3.7 2.5 4
3102303 115 - 118 340 BTU/H [100W] 24 VDC 7.4 4.9 8 No
3152303 170 - 180 510 BTU/H [150W] 11 7.5 10
3200303 260 - 280 680 BTU/H [200W] 17 11.6 16
Notes: Power and Cooling Capacity values are for 95°F [35°C] internal and ambient temperatures. Refer to Performance Graphs for values
corresponding to other conditions.
Fuses are Class T Time Delay.

Airflow Example

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Vortex Coolers
Features Compressed air is injected into the vortex
tube at extremely high speeds and that
• Relief valves and seals built into the vortex creates a cyclone, or vortex, spinning a
coolers which enable the units to maintain million revolutions per minute. Part of the
the sealed nature of NEMA enclosures
air is forced to spin inward to the center
• No freon and travels up a long tube where a valve
• Small physical size turns the spinning column of air inside
• Creates cool air without refrigerants (no itself. The inside column of air gives up its
CFCs, HCFCs) heat to the outside column. The cold air
• Exceptionally reliable - no moving parts and is directed out the cold end of the Vortex
virtually no maintenance Tube and the hot air is directed out the
• No fans other end of the Vortex Tube. And since
there are no moving parts there is little
• Stainless steel construction
need for maintenance.
• All replacement generators fit any of the
vortex coolers. No need to purchase a new
cooler if you need to change your
cooling capacity

Applications • 5-year warranty

Compressed air cooling is used where

conventional enclosure cooling byair
Requirements
conditioners or heat exchangers is not • Uses clean, dry, oil-free compressed air (80
possible. (Examples: Small to medium size to 100 PSIG / 70° F or below) required to
enclosures, nonmetallic enclosures, and achieve published BTU/H ratings. Lower
pressures and/or higher temperatures will
areas where the size of cooling devices is reduce BTU/H rating
restricted)
• A 5-micron water and particulate removal
filter must be installed prior to any vortex
Mounting holes cooler operation
• An oil removal filter can be installed between
• Mounts in a 0.25in [6 mm] electrical conduit
the 5-micron filter and the Vortex Cooler if
knockout
oil is present in the compressed air line
• Thermostats, filters, regulators, and valves
Agency Approvals that work with Stratus Vortex Coolers are
sold separately. Kits that include these items
• UL Recognized component [File E329932]UL/ are listed later in this section
NEMA 4, 4X
• Operation above 100 PSIG is not
recommended. The use of a pressure
regulator will be necessary for
higher pressures
• How vortex coolers create cold air

Air Consumption SCFM

Part Type Part Number Price Description Capacity BTUH [W]
[SLPM]
Stratus vortex cooler, stainless steel body. For NEMA 4/4X/12
TV08-005-4X $362.00 500 [147] 8 [227]
enclosures. Distribution tube and muffler included.
Stratus vortex cooler, stainless steel body. For NEMA 4/4X/12
TV10-006-4X $362.00 600 [176] 10 [283]
enclosures. Distribution tube and muffler included.
Stratus vortex cooler, stainless steel body. For NEMA 4/4X/12
Vortex Coolers TV15-010-4X $362.00 1000 [293] 15 [425]
enclosures. Distribution tube and muffler included.
Stratus vortex cooler, stainless steel body. For NEMA 4/4X/12
TV25-018-4X $362.00 1800 [528] 25 [708]
enclosures. Distribution tube and muffler included.
Stratus vortex cooler, stainless steel body. For NEMA 4/4X/12
TV35-025-4X $362.00 2500 [732] 35 [991]
enclosures. Distribution tube and muffler included.
Stratus vortex generator, replacement, polypropylene, white. Fits all
TV08-G $11.25 500 [147] 8 [227]
Stratus TV series vortex cooler bodies.
Stratus vortex generator, replacement, polypropylene, orange. Fits all
TV10-G $11.25 600 [176] 10 [283]
Stratus TV series vortex cooler bodies.
Replacement Stratus vortex generator, replacement, polypropylene, red. Fits all
TV15-G $11.25 1000 [293] 15 [425]
Generators Stratus TV series vortex cooler bodies.
Stratus vortex generator, replacement, polypropylene, blue. Fits all
TV25-G $11.25 1800 [528] 25 [708]
Stratus TV series vortex cooler bodies.
Stratus vortex generator, replacement, polypropylene, yellow. Fits all
TV35-G $11.25 2500 [732] 35 [991]
Stratus TV series vortex cooler bodies.

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Enclosure Cooling –
Selecting a Heat Exchanger
Heat exchanger selection Heat Exchanger Selection Example
To select the proper size heat exchanger, the worst-case A NEMA 12 Wiegmann N12302412 enclosure (30 in [762 mm]
conditions should be considered. For a heat exchanger to high x 24 in [610 mm] wide x 12 in [305 mm] deep) contains a
work, the ambient air temperature must be lower than the GS3-4010 AC drive 10 HP 460 volt) that has a maximum allowable
desired internal enclosure air temperature. operating temperature of 104°F and is located in a warehouse that
has a maximum outside ambient air temperature of 90°F.
There are three main factors in choosing a heat exchanger for
an uninsulated metal NEMA rated enclosure located indoors: Power to be dissipated is stated in the specifications of the GS3-
4010 and is found to be 345 watts.
• Internal heat load
Internal heat load:
• Delta T
• Heat load transfer Internal Heat Load = 345 Watts
Delta T:
Internal Heat Load
Internal heat load is the heat generated by the components ΔT (°F) 104°F – 90°F = 14°F
inside the enclosure. This can be determined by a few Heat load transfer:
different methods. The preferred method is to add the Surface Area (ft.2) = 2 [(30 x 24) + (30 x 12) + (24 x 12)] / 144 sq. inches = 19 ft.2
maximum heat output specifications that the manufacturers Heat Load Transfer = 0.22 x 19 ft2 = 4.2 Watts/°F
list for all the equipment installed in the cabinet. This is Cooling capacity:
typically given in Watts. Cooling Capacity = 345 Watts/14°F - 4.2 Watts/°F = 20.4 Watts/°F
Delta T (ΔT) In this example, you are able to determine that a Stratus heat
Delta T = maximum allowable internal enclosure temperature exchanger, with a capacity of at least 20.4 Watts/°F is needed, such
°F – maximum outside ambient temperature °F. as a TE30-030-17-04.
Heat Load Transfer *This selection procedure applies to metal and non-metal,
Heat load transfer is the heat lost (negative heat load transfer) uninsulated, sealed enclosures in indoor locations. This selection
or gained (positive heat load transfer) through the enclosure procedure gives the minimum required size; be careful not to
walls with the surrounding ambient air. This can be calculated undersize when purchasing.
by the following formulas:
Surface Area (sq. ft.) = 2 [(H x W) + (H x D) + (W x D)] / (144
sq. inches/sq. ft.)
Note: Only include exposed surfaces of enclosue in
calculations. Exclude surfaces such as a surface mounted to a
wall.
Heat Load Transfer (W/°F) = 0.22 W/°F sq. ft. x surface area
Note: Use 0.22 Watts/°F sq. ft. for painted steel and non-
metallic enclosures. Use.10 Watts/°F sq. ft. for stainless steel
and bare aluminum enclosures.
Cooling Capacity
Once you have determined your Internal Heat Load, the Heat
Load Transfer and the Delta T, you can choose the proper size
unit by calculating the needed cooling capacity.
Cooling Capacity (W/°F) = Internal Heat Load / ∆T - Heat
Load Transfer

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Air To Air Heat Exchangers

Consider a Better Construction
Solution: Air to Air Heat • Heat pipe technology

Exchanger • Closed loop design

• Always closed loop

• Low cost
Listings
• UL File: SA34086
• Easier to mount on only one side of
your enclosure • Made in USA
• Energy efficient; uses no more power than a
filtered fan system Features
• Filter-free; no diminished cooling capacity
• All units are available in NEMA 4 and 4X
• Available in 120 VAC and 24 VDC
Applications • Motors have a sealed overload protector
A closed loop cooling system which • Finned evaporator and condenser sections
employs the heat pipe principle to provide a closed loop
exchange heat from an electrical • Coil systems use aluminum end plates and Tall, compact, and deep body
enclosure to the outside. baffles which improve conduction and styles shown
reduce corrosion for longer life
• UL/cUL listed

Air to Air Heat Exchange

The Air to Air Heat Exchanger is a closed loop
cooling system which employs the heat pipe
principle to exchange heat from an electrical
enclosure to the outside. Where ambient
temperatures are suitable for heat pipes, they are
the most efficient method of cooling as the waste
heat is the engine which drives the system. The only
power requirement is to operate two circulating fans
or blowers.
Heat pipes have a liquid refrigerant under a partial
vacuum inside sealed tubes. They operate with
a phase change process which is much like that
of mechanical air conditioning, but without the
compressor. Each heat pipe has an evaporator
section and a condenser section which are separated
by a permanent baffle so as to provide a closed
loop. The bottom of each heat pipe is in contact
with heated air from the electrical enclosure. When
the enclosure air reaches approximately 75° F, the
refrigerant changes to vapor phase (boils) and the
vapor (steam) rises to the top of the tube which is in
contact with cooler outside (ambient) air.
When the outside air temperature is lower than the
enclosure temperature, the refrigerant vapor gives
up heat to the outside air and returns to the liquid
phase. It then falls to the bottom and repeats the
cycle endlessly so long as there is a negative temperature differential between the enclosure and outside. Heat pipes will not operate
in reverse cycle so heat cannot be transferred from the ambient to the interior of the enclosure. Although the operation is self limiting,
thermostatic control can be used to shut off the fans when not needed.
The Stratus design has a top-to-bottom enclosure air flow pattern with maximum separation of the inlet and outlet. This design pulls
the hottest air from the top of the enclosure and returns the cooled air from the bottom of the heat pipe to the enclosure. The air flow
on the ambient side is bottom in, top out, so that the hotter discharge air moves up and away rather than being recirculated.
The units use aluminum end plates and baffles which improve conduction and reduce corrosion for longer life. The center aluminum
baffle, which is swaged into the heat pipe coil, provides an air tight seal between the two air systems.

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Air To Air Heat Exchanger

Specifications

In this image, a standard In this image, a standard

installation shows where installation demonstrates
the dirt and particulate the closed loop condition
will enter the enclosure maintained by the Air to
and be pulled in by the Air Heat Exchanger. Cool
fans on your drives and air inlet and outlet vents
devices. Filters or not, are completely covered
contamination is invited in by the heat exchanger.
by this open This provides NEMA type
loop approach. 4 or 4X.

Stratus Air to Air Heat Exchangers General Specifications

TE20-015-24D-4X

TE30-030-24D-4X

TE40-050-24D-4X
TE20-015-24D-04

TE30-030-24D-04

TE40-050-24D-04
TE20-015-17-4X

TE30-030-17-4X

TE40-050-17-4X
TE20-015-17-04

TE30-030-17-04

TE40-050-17-04
Part Number

Price $1,800.00 $1,881.00 $1,853.00 $1,933.00 $1,860.00 $1,996.00 $1,912.00 $2,043.00 $2,433.00 $2,530.00 $2,560.00 $2,657.00
Operating Voltage
± 10%
Range (V)
Inrush Current (Start
1.92 3.90 1.92 3.90 2.59 9.70
Up Current) (A)
Loading Current
0.37 0.80 0.37 0.80 0.47 1.94
(Running Current) (A)
SCCR (Short Circuit
Refer to Footnote 1
Current Rating) (A)
Recommended Circuit
Protection Device 1.5 2.5 1.5 2.5 2 6
Rating (A)
VA Rating (W) 42 20 42 20 56 47
Methanol Methanol Methanol Methanol
Refrigerant Type (oz)
(0.41) (0.41) (0.81) (1.22)
Watts/°C (F°) ­­22 (12) 44 (24) 71.6 (40)
Free Air Flow (CFM) 131 127 131 127 211 235
Weight Without
16 19 32
Packaging (lbs)
Body Style compact deep tall
2CRS 2CRS 2CRS 2CRS 2CRS 2CRS
with ANSI with ANSI with ANSI with ANSI with ANSI with ANSI
3Stainless 3Stainless 3Stainless 3Stainless 3Stainless 3Stainless
Material Type 61 gray 61 gray 61 gray 61 gray 61 gray 61 gray
Steel Steel Steel Steel Steel Steel
powder powder powder powder powder powder
coat coat coat coat coat coat
Voltage/Hz 120 VAC 50/60 24 VDC 120 VAC 50/60 24 VDC 120 VAC 50/60 24 VDC
Maximum Ambient
160°F (71.1°C)
Temperature
Agency Approval UL File: SA34086
Notes: 1 SCCR rating is based on the SCCR rating for the circuit protection device installed in the panel / enclosure per UL50 and UL508a to protect the AC unit Typically
10KA for Fast Acting Fuses.
2
Cold-rolled steel with ANSI-61 gray polyester powder coating inside and out.
3
Fabricated from 16-gauge 304 stainless steel.

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