60079-17 © IEC:2013 – 25 –

Explosion protected equipment to type of protection “'nL” shall be inspected in accordance

with Table 2 (see 5.3).

5.5.2 Restricted breathing enclosures

Restricted breathing enclosures with provision for routine checking shall be subjected to
periodic pressure test measurement (see IEC 60079-15) at intervals of six months or more, as
experience dictates.

5.6 Type of protection “t” and “tD” – Protection by enclosure (see Table 1 and
IEC 60079-31 and IEC 61241-1)

Explosion protected equipment type “t” and “tD” shall be inspected in accordance with Table 1.

5.7 Types of protection “m” and “mD” (encapsulation), “o”, (oil-immersion) “op”
(optical radiation) and “q” (powder-filling)

Tables have not been prepared to illustrate the inspection requirements for “m”, “mD”, “o”,
“op” and “q” types of protection. Table 1 should be utilised as appropriate for the enclosure
and its contents.

NOTE Inspection details for type of protection ”o” are under consideration in IEC 60079-6.

6 Inspection tables

Table 1 – Inspection schedule for Ex “d”, Ex “e”, Ex “n” and Ex “t/tD”

Ex “d” Ex “e” Ex “n”

Check that: Ex“t/tD”

X = required for all types, n = type “n” only, t = type “t” and “tD” only Grade of inspection
D C V D C V D C V
A GENERAL (ALL EQUIPMENT)

1 Equipment is appropriate to the EPL/Zone requirements of the location X X X X X X X X X

2 Equipment group is correct X X X X X X
3 Equipment temperature class is correct (only for gas) X X X X n n
4 Equipment maximum surface temperature is correct t t
5 Degree of protection (IP grade) of equipment is appropriate for the level of X X X X X X X X X
protection/group/conductivity
6 Equipment circuit identification is correct X X X
7 Equipment circuit identification is available X X X X X X X X X
8 Enclosure, glass parts and glass-to-metal sealing gaskets and/or compounds X X X X X X X X X
are satisfactory
9 There is no damage or unauthorized modifications X X X
10 There is no evidence of unauthorized modifications X X X X X X
11 Bolts, cable entry devices (direct and indirect) and blanking elements are of the
correct type and are complete and tight
– physical check X X X X X X
– visual check X X X
12 Threaded covers on enclosures are of the correct type, are tight and secured
– physical check X X
– visual check X
13 Joint surfaces are clean and undamaged and gaskets, if any, are satisfactory X
and positioned correctly
 – 26 – 60079-17 © IEC:2013

Ex “d” Ex “e” Ex “n”

Check that: Ex“t/tD”

X = required for all types, n = type “n” only, t = type “t” and “tD” only Grade of inspection
D C V D C V D C V
14 Condition of enclosure gaskets is satisfactory X X X
15 There is no evidence of ingress of water or dust in the enclosure in accordance X X X
with the IP rating
16 Dimensions of flanged joint gaps are: X
– within the limits in accordance with manufacturer’s documentation or
– within maximum values permitted by relevant construction standard at time
of installation or
– within maximum values permitted by site documentation
17 Electrical connections are tight X X
18 Unused terminals are tightened X n
19 Enclosed-break and hermetically sealed devices are undamaged n
20 Encapsulated components are undamaged X n
21 Flameproof components are undamaged X n
22 Restricted breathing enclosure is satisfactory – ( type “nR” only) n
23 Test port, if fitted, is functional– ( type “nR” only) n
24 Breathing operation is satisfactory– ( type “nR” only) X X n
25 Breathing and draining devices are satisfactory X X X X n n
EQUIPMENT SPECIFIC (LIGHTING)

26 Fluorescent lamps are not indicating EOL effects X X X X X X

27 HID lamps are not indicating EOL effects X X X X X X X X X
28 Lamp type, rating, pin configuration and position are correct X X X
EQUIPMENT SPECIFIC (MOTORS)

29 Motor fans have sufficient clearance to the enclosure and/or covers, cooling
X X X X X X X X X
systems are undamaged, motor foundations have no indentations or cracks.
30 The ventilation airflow is not impeded X X X X X X X X X
31 Insulation resistance (IR) of the motor windings is satisfactory X X X
B INSTALLATION – GENERAL

1 Type of cable is appropriate X X X

2 There is no obvious damage to cables X X X X X X X X X
3 Sealing of trunking, ducts, pipes and/or conduits is satisfactory X X X X X X X X X
4 Stopping boxes and cable boxes are correctly filled X
5 Integrity of conduit system and interface with mixed system maintained X X X
6 Earthing connections, including any supplementary earthing bonding
connections are satisfactory (for example connections are tight and conductors
are of sufficient cross-section)
– physical check X X X
– visual check X X X X X X
7 Fault loop impedance (TN systems) or earthing resistance (IT systems) is X X X
satisfactory
8 Automatic electrical protective devices are set correctly (auto-reset not X X X
possible)
9 Automatic electrical protective devices operate within permitted limits X X X
10 Specific conditions of use (if applicable) are complied with X X X
60079-17 © IEC:2013 – 27 –

Ex “d” Ex “e” Ex “n”

Check that: Ex“t/tD”

X = required for all types, n = type “n” only, t = type “t” and “tD” only Grade of inspection
D C V D C V D C V
11 Cables not in use are correctly terminated X X X
12 Obstructions adjacent to flameproof flanged joints are in accordance with X X X
IEC 60079-14
13 Variable voltage/frequency installation complies with documentation X X X X X X
INSTALLATION – HEATING SYSTEMS

14 Temperature sensors function according to manufacturer’s documents X X t

15 Safety cut off devices function according to manufacturer’s documents X X t
16 The setting of the safety cut off is sealed X X X X
17 Reset of a heating system safety cut off possible with tool only X X X X
18 Auto-reset is not possible X X X X
19 Reset of a safety cut off under fault conditions is prevented X X
20 Safety cut off independent from control system X X
21 Level switch is installed and correctly set, if required X X
22 Flow switch is installed and correctly set, if required X X
INSTALLATION – MOTORS

23 Motor protection devices operate within the permitted t E or t A time limits. X

C ENVIRONMENT

1 Equipment is adequately protected against corrosion, weather, vibration and X X X X X X X X X

other adverse factors
2 No undue accumulation of dust and dirt X X X X X X X X X
3 Electrical insulation is clean and dry X X
(D = detailed, C = close, V = visual)
 – 28 – 60079-17 © IEC:2013

Table 2 – Inspection schedule for Ex “i” installations

Grade of
Check that:
inspection
X = required
D C V
A EQUIPMENT

1 Circuit and/or equipment documentation is appropriate to the EPL/Zone X X X

2 Equipment installed is that specified in the documentation X X
3 Circuit and/or equipment category and group correct X X
4 IP rating of equipment is appropriate to the Group III material present X X
5 Equipment temperature class is correct X X
6 Ambient temperature range of the apparatus is correct for the installation X X
7 Service temperature range of the apparatus is correct for the installation X X
8 Installation is clearly labelled X X
9 Enclosure, glass parts and glass-to-metal sealing gaskets and/or compounds are satisfactory X
10 Cable glands and blanking elements are the correct type, complete and tight X X X
– physical check
– visual check
11 There are no unauthorized modifications X
12 There is no evidence of unauthorized modifications X X
13 Diode safety barriers, galvanic isolators, relays and other energy limiting devices are of the X X X
approved type, installed in accordance with the certification requirements and securely
earthed where required
14 Condition of enclosure gaskets is satisfactory X
15 Electrical connections are tight X
16 Printed circuit boards are clean and undamaged X
17 The maximum voltage U m of the associated apparatus is not exceeded X X
B INSTALLATION

1 Cables are installed in accordance with the documentation X

2 Cable screens are earthed in accordance with the documentation X
3 There is no obvious damage to cables X X X
4 Sealing of trunking, ducts, pipes and/or conduits is satisfactory X X X
5 Point-to-point connections are all correct (initial inspection only) X
6 Earth continuity is satisfactory (e.g. connections are tight, conductors are of sufficient cross- X
section) for non-galvanically isolated circuits
7 Earth connections maintain the integrity of the type of protection X
8 Intrinsically safe circuit earthing is satisfactory X
9 Insulation resistance is satisfactory X
10 Separation is maintained between intrinsically safe and non-intrinsically safe circuits in X
common distribution boxes or relay cubicles
11 Short-circuit protection of the power supply is in accordance with the documentation X
12 Specific conditions of use (if applicable) are complied with X
13 Cables not in use are correctly terminated X
C ENVIRONMENT

1 Equipment is adequately protected against corrosion, weather, vibration and other adverse X X X
factors
2 No undue external accumulation of dust and dirt X X X
60079-17 © IEC:2013 – 29 –

Table 3 – Inspection schedule for Ex “p” and “pD” installations

Grade of
Check that:
inspection
X = required
D C V
A EQUIPMENT
1 Equipment is appropriate to the EPL/zone requirements of the location X X X
2 Equipment group is correct X X
3 Equipment temperature class or surface temperature is correct X X
4 Equipment circuit identification is correct X
5 Equipment circuit identification is available X X X
6 Enclosure, glasses and glass-to-metal sealing gaskets and/or X X X
compounds are satisfactory
7 There are no unauthorized modifications X
8 There is no evidence of unauthorized modifications X X
9 Lamp type, rating, and position are correct X
B INSTALLATION
1 Type of cable is appropriate X
2 There is no obvious damage to cables X X X
3 Earthing connections, including any supplementary earthing bonding X X X
connections, are satisfactory, for example connections are tight and
conductors are of sufficient cross-section
– physical check
– visual check
4 Fault loop impedance (TN systems) or earthing resistance (IT systems) is satisfactory X
5 Automatic electrical protective devices operate within permitted limits X
6 Automatic electrical protective devices are set correctly X
7 Protective gas inlet temperature is below maximum specified X
8 Ducts, pipes and enclosures are in good condition X X X
9 Protective gas is substantially free from contaminants X X X
10 Protective gas pressure and/or flow is adequate X X X
11 Pressure and/or flow indicators, alarms and interlocks function correctly X
12 Conditions of spark and particle barriers of ducts for exhausting the gas X
in hazardous area are satisfactory
13 Specific conditions of use (if applicable) are complied with X
C ENVIRONMENT
1 Equipment is adequately protected against corrosion, weather, vibration X X X
and other adverse factors
2 No undue accumulation of dust and dirt X X X
(D = detailed, C = close, V = visual)