PROJECT: The Medical Complex ‫ المنطقة االستثمارية لجامعة القاهر‬- ‫ المجمع الطبي‬:‫المشروع‬

The Investment Zone of Cairo University - Sixth of October City ‫بمدينة السادس من اكتوبر‬
STAGE 3 – Issue For Tender Stage ‫المرحلة الثالثة – مرحلة العطاءات‬

SECTION 16461

DRY-TYPE TRANSFORMERS

PART 1 - GENERAL

1.1 SECTION INCLUDES

A. Furnishing and installation of and testing of cast resin dry type MV/LV distribution
transformer in accordance with specifications and drawings. Any material or
equipment necessary for the proper operation not specified or described herein
shall be deemed part of the specifications.

1.2 REFERENCES

A. IEC - International Electrotechnical Commission

IEC 60076-1 to 5 Power transformers

IEC 60726 Dry type power transformers

IEC 60905 Loading guide for dry-type power transformers.

B. CENELEC Harmonisation Documents:

- HD 464 S1: 1988 + / A2: 1991 + / A3: 1992 for dry-type power transformers
- HD 538-1 S1: 1992 for three-phase dry-type distribution transformers from
100 to 2500 KVA with highest voltage for equipment not exceeds 22 KV.

C. NFPA - National Fire Protection Association

NFPA 70 National Electric Code

1.3 SUBMITTALS

A. Shop Drawings and Manufacturer's Data: The contractor shall submit to the
Engineer for review, detailed dimensioned shop drawings and manufacturer's
literature where deviations from the contract drawings or specification exist. Shop
drawings and/or data sheets shall be based on information stated in the
specifications and as shown on the contract drawings and shall show all
pertinent deviations and data for the fabrication and complete installation.

Manufacturer's data sheets shall be submitted indicating the necessary

installation dimensions, weights, materials and performance information. The
above information may be provided by standard catalogue sheets marked to
indicate the specific items provided.
Project No: CUIZ - MC - 001 Dry-Type Transformers
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D.A.D Consultants
PROJECT: The Medical Complex ‫ المنطقة االستثمارية لجامعة القاهر‬- ‫ المجمع الطبي‬:‫المشروع‬
The Investment Zone of Cairo University - Sixth of October City ‫بمدينة السادس من اكتوبر‬
STAGE 3 – Issue For Tender Stage ‫المرحلة الثالثة – مرحلة العطاءات‬

B. Operation and Maintenance Instructions: The contractor shall furnish data

covering model, type and serial numbers, capacities, maintenance and operation
of each major item of equipment or apparatus in accordance with the
requirements of the contract documents. Operating instructions shall cover all
phases of control.

C. Test Reports: The contractor shall submit test reports to the Engineer for review.

D. Recommended Spare Parts List: The contractor shall submit recommended

spare parts list to the Engineer for review.

E. As Built Drawings: The contractor shall submit the as built drawings to the
Engineer for review and approval.

1.4 QUALITY ASSURANCE

A. All materials and products shall be new, sound and uniform in quality, size,
shape, color and texture and shall be free from defects. The work shall be carried
out in accordance with this specification, the contract drawings and the standards
listed hereunder. The codes and standards specified herein provide an
acceptable level of quality for materials and products. Equipment shall
conforming to the altitude of site.

B. The work shall be carried out in accordance with this specification, the contract
drawings and the standards listed herein. The referenced codes and standards
provide an acceptable level of quality for materials and products:

C. The contractor shall be responsible for ensuring that the required standards of
quality control as mentioned in relative sections are maintained for the proposed
transformers.

D. If requested by the Engineer, the supplier shall provide proof of application of a

quality procedure complying with standards. This means:

1. Use of a quality manual approved and signed by a management

representative,
2. Regular updating of this manual so that it reflects the most recent
applicable quality control procedures,
3. ISO 9002 certification.

E. The manufacturer must have a sound experience in the field of transformers for
not less than ten years, and should have a presentable reference list of the
already supplied equipment of the same type and same make and that this
equipment has been in satisfactory operation.

1.5 COORDINATION

Project No: CUIZ - MC - 001 Dry-Type Transformers

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PROJECT: The Medical Complex ‫ المنطقة االستثمارية لجامعة القاهر‬- ‫ المجمع الطبي‬:‫المشروع‬
The Investment Zone of Cairo University - Sixth of October City ‫بمدينة السادس من اكتوبر‬
STAGE 3 – Issue For Tender Stage ‫المرحلة الثالثة – مرحلة العطاءات‬

A. The contractor shall be held responsible for the proper coordination of all phases
of the work under this contract.

B. It shall be the responsibility of the contractor to coordinate the work and

equipment as specified herein with work to be performed and equipment to be
furnished under other sections of the specifications in order to assure a complete
and satisfactory installation.

1.6 TRANSPORTATION, HANDLING AND STORAGE

A. Deliver, store, protect and handle products to site as per manufacturer’s

instructions.

B. Store transformers in clean and dry space. Inspect for damage. Maintain factory
wrapping or provide an additional heavy canvas or heavy plastic cover to protect
units from dirt, water, construction debris and traffic.

C. Lift only with lugs provided for the purpose. Handle carefully to avoid damage to
transformer internal components, enclosure and finish.

1.7 WARRANTY

A. Submit written guarantee signed by the contractor and manufacturer for the period of
one year from the date of substantial completion. The guarantee shall cover the
repair and replacement of defective materials and workmanship as directed by the
Engineer.

PART 2 - PRODUCTS

2.1 GENERAL

A. The following specifications apply to three-phase transformers of cast resin type,

class F insulation system with natural (AN) cooling for indoor installation,
destined for use in three-phase MV/LV distribution systems.

B. Forced cooling (AF) shall be provided to increase the rated power up to 40%.

2.2 GENERAL REQUIREMENTS

A. General

1. The transformers shall be of climatic class C2 and of environmental class

E2 as defined in appendix B of HD 464 S1: 1988 / A2: 1991. C2 and E2
classes shall be indicated on the rating plate.

2. The transformers shall be of fire behaviour class F1 as defined in article B3

of CENELEC HD 464 S1: 1988 / A2: 1991. F1 class shall be indicated on
Project No: CUIZ - MC - 001 Dry-Type Transformers
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PROJECT: The Medical Complex ‫ المنطقة االستثمارية لجامعة القاهر‬- ‫ المجمع الطبي‬:‫المشروع‬
The Investment Zone of Cairo University - Sixth of October City ‫بمدينة السادس من اكتوبر‬
STAGE 3 – Issue For Tender Stage ‫المرحلة الثالثة – مرحلة العطاءات‬

the rating plate.

3. All electrical equipment shall be suitable to operate at altitude of 2250 m

above sea level.

A. Magnetic Core

1. This shall be made from laminations of grain oriented silicon steel, insulated
with mineral oxide and shall be protected against corrosion with a coat of
varnish.

B. LV Windings

1. These shall be made from copper foil with class F interlayer insulation by
encapsulation (impregnation) with synthetic alkyd resin or equivalent.
2. At least the upper part of the LV coils shall be covered with a coat of epoxy
resin or equivalent and the foil shall be protected everywhere with an
insulation material even in the air ducts.

C. MV Windings

1. These shall be independent of the LV windings and shall be made of

copper wire or foil with class F insulation.
2. The MV windings shall be vacuum cast in a class F fireproof epoxy resin
casting system composed of:
- An epoxy resin
- An anhydride hardener with a flexibilising additive
- A flame-retardant filler.
3. The flame-retardant filler shall be thoroughly mixed with the resin and
hardener. It shall be composed of trihydrated alumna powder (or aluminum
hydroxide) or other flame-retardant products to be specified, either mixed
with silica or not.
4. The casting system shall be of class F.

D. MV Connections

1. The MV connections shall be made from above on the top of the

connection bars. Each bar shall be drilled with a 13-mm hole ready for
connection of cable lugs on terminal plates.

2. The MV connection bars shall be in rigid copper bars protected by heat

shrinkable tubing.
3. MV connections in cables are not allowed.
4. The MV connections shall be copper.

E. LV Connections

Project No: CUIZ - MC - 001 Dry-Type Transformers

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D.A.D Consultants
PROJECT: The Medical Complex ‫ المنطقة االستثمارية لجامعة القاهر‬- ‫ المجمع الطبي‬:‫المشروع‬
The Investment Zone of Cairo University - Sixth of October City ‫بمدينة السادس من اكتوبر‬
STAGE 3 – Issue For Tender Stage ‫المرحلة الثالثة – مرحلة العطاءات‬

1. The LV connections shall be made from above onto bars located at the top
of the coils on the opposite side to the MV connections.
2. Connection of the LV neutral shall be directly made to the LV terminals
between the LV phase bars.
3. The LV connection bars shall be copper and shall accept busway or cable
as shown on drawings.

F. MV Tapping

1. The tapping which act on the highest voltage adapting the transformer to
the real supply voltage value, shall be off-circuit bolted links.
2. Tapping with connection cables is not allowed.
3. These bolted links shall be attached to the MV coils.

2.3 METAL ENCLOSURE

A. The transformers shall be equipped with a metal enclosure for indoor installation
comprising an integral IP 31 (except the base which may be IP 21) metal
enclosure with:

1. An anti-corrosion protection in the manufacturer's standard color.

2. Lifting lugs enabling the transformer and enclosure assembly to be
handled.
3. A bolted access panel on the enclosure front to allow access to the MV
connections and to the tapping. This shall be fitted with handles; it shall
have one "Danger Electricity" warning label (T 10 warning), a rating plate
and a visible braid for earthling.

4. Blanked off holes for fitting key locks on the bolted access panel to enable
it to be locked.
5. 2 UN-drilled gland plates on the roof: one on the MV side, one on the LV
side (drilling and cable gland not supplied).
6. 1 plate at the right MV side on the bottom of the enclosure for the MV
cables for connections from the bottom.

2.4 ACCESSORIES AND STANDARD EQUIPMENT

A. The transformers shall be equipped with:

Project No: CUIZ - MC - 001 Dry-Type Transformers

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PROJECT: The Medical Complex ‫ المنطقة االستثمارية لجامعة القاهر‬- ‫ المجمع الطبي‬:‫المشروع‬
The Investment Zone of Cairo University - Sixth of October City ‫بمدينة السادس من اكتوبر‬
STAGE 3 – Issue For Tender Stage ‫المرحلة الثالثة – مرحلة العطاءات‬

1. 4 flat bi-directional rollers

2. 2 lifting lugs
3. Haulage holes on the under base
4. 2 earthling terminals
5. 1 rating plate
6. 1 "Danger Electricity" warning label
7. 1 routine tests certificate
8. 1 instruction manual for installation, commissioning and maintenance in
English.

B. Thermal protection

1. The transformers shall be equipped with a thermal protection device, which

shall comprise:
- 2 sets of 3 PTC sensors, one sensor for "Alarm 1", one for "Alarm 2" per
phase, installed in the coils of the transformer. They shall be placed in a
tube to enable them to be replaced when ever necessary.
- An electronic converter with two independent monitoring circuits
equipped with a changeover switch, one for "Alarm 1" and the other for
"Alarm 2". The position of the relays shall be indicated by different
colored indicator lights. A third indicator light shall indicate the presence
of voltage.
2. The three indicator lights shall be on the front of the converter. The
electronic converter shall be installed away from the transformer.
3. A plug-in terminal block shall be provided for connection of the PTC
sensors to the electronic converter.
4. The PTC sensors shall be supplied assembled and wired to the terminal
block fixed on the upper part of the transformer. The converter shall be
supplied loose with the transformer, packaged complete with its wiring
diagram.

2.5 TYPE TESTS AND ROUTINE TESTS

A. Routine Tests

The following tests shall be carried out on all the transformers after the
manufacturing, enabling an official test certificate to be produced for each one:

1. Measurement of windings resistance.

2. Measurement of the transformation ratio and vector group
3. Measurement of impedance voltage and load loss
4. Measurement of no load loss and no load current
5. Applied voltage dielectric test
6. Induced voltage dielectric test

(All these tests shall be in accordance with Harmonisation Document HD 464 S1,
the IEC 60726 and IEC 60076-1 to 60076-5 standards).

Project No: CUIZ - MC - 001 Dry-Type Transformers

16461-6
D.A.D Consultants
PROJECT: The Medical Complex ‫ المنطقة االستثمارية لجامعة القاهر‬- ‫ المجمع الطبي‬:‫المشروع‬
The Investment Zone of Cairo University - Sixth of October City ‫بمدينة السادس من اكتوبر‬
STAGE 3 – Issue For Tender Stage ‫المرحلة الثالثة – مرحلة العطاءات‬

B. Type Tests Special Tests

The following tests may be requested by the Engineer:

1. Temperature rise test carried out in accordance with the simulated loading
method as defined by the IEC 60726 standard.
2. Lightning impulse test.
3. Short circuit test.
4. Noise level measurements in accordance with IEC 60551.
5. Measurement of partial discharges.

For measurement of the partial discharges, the acceptance criterion shall be:

- Partial discharges less than or equal to 10 pC at 1.10 Um.

If Um > 1.25 Un (Un = rated voltage, Um = system highest voltage), then the
10 pC are guaranteed at 1.375 Un.

(All these tests shall be in accordance with Harmonisation Document HD 464 S1,
the IEC 60726 and IEC 60076-1 to 60076-5 standards).

6. The climate and environmental tests shall be performed in accordance with

appendix ZA and ZB of CENELEC HD 464 S1: 1988 / A3: 1992.
7. The fire behaviour test shall be performed in accordance with appendix ZC
of CENELEC HD 464 S1: 1988 / A3: 1992.

2.6 Transformer Technical Data

Project No: CUIZ - MC - 001 Dry-Type Transformers

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D.A.D Consultants
 PROJECT: The Medical Complex ‫ المنطقة االستثمارية لجامعة القاهر‬- ‫ المجمع الطبي‬:‫المشروع‬
The Investment Zone of Cairo University - Sixth of October City ‫بمدينة السادس من اكتوبر‬
STAGE 3 – Issue For Tender Stage ‫المرحلة الثالثة – مرحلة العطاءات‬

For each requested transformer, the supplier shall give the following data :

Rated power ....................................................................... As per drawings KVA

Cooling .................................................................................... ...AN and AF
Rated frequency ....................................................................................... 50 Hz
Primary voltage ......................................................................................... 22 KV
Rated primary insulation level ................................................................... 24 KV
Power frequency withstand Voltage(rms) ................................................ 50 KV
Basic Insulation Level (BIL) or impulse withstand voltage (peak) ........... 125 KV
Off-circuit tapping .............................................................................. +/- 2.5 %
Secondary voltage at No- Load

- For 380V system, No-Load Voltage : 400V

- For 220V system, No-Load Voltage : 231V

Vector group ...................................................................................... Dyn11

No load losses .............................................................................................. W

Load losses at 75° C..................................................................................... W
Load losses at 120° C................................................................................... W
Rated impedance voltage at 120° C ............................................................. %
Acoustic power Lw(A) ................................................................................... dB(A)
Acoustic pressure at 1 meter Lp(A) .............................................................. dB(A)

Maximum ambient temperature .................................................................... °C

Daily average ambient temperature .............................................................. °C
Yearly average ambient temperature ............................................................ °C
altitude .......................................................................................................... m

MV winding temperature class ...................................................................... F

LV winding temperature class ....................................................................... F
Temperature of insulation system ................................................................. 155 °C

Climatic classification (HD 464 S1) ............................................................... C2

Environmental classification (HD 464 S1) .................................................... E2
Fire behaviour classification (HD 464 S1) ..................................................... F1

Enclosure ...................................................................................................... YES

Protection degree ......................................................................................... IP 31

Length........................................................................................................... mm
Width ............................................................................................................ mm
Height ........................................................................................................... mm
Total weight .................................................................................................. kg

Project No: CUIZ - MC - 001 Dry-Type Transformers

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 PROJECT: The Medical Complex ‫ المنطقة االستثمارية لجامعة القاهر‬- ‫ المجمع الطبي‬:‫المشروع‬
The Investment Zone of Cairo University - Sixth of October City ‫بمدينة السادس من اكتوبر‬
STAGE 3 – Issue For Tender Stage ‫المرحلة الثالثة – مرحلة العطاءات‬

Measurement circuit supply voltage for the thermal protection electronic

Converter ........................................................................................ DC AC V

PART 3 - EXECUTION

3.1 WORKMANSHIP

A. Materials, products and equipment furnished by the contractor, shall be installed

and all work shall be performed in a first-class workmanship manner, in
conformity with the best trade practices and the printed directions of the
applicable manufacturers; by skilled workers equipped to produce satisfactory
results; in a safe, substantial manner so as to avoid undue stresses, rigid enough
to prevent undue movement, so as to present a neat, orderly appearance and to
facilitate operating, servicing, maintenance and repairing.

3.2 FOUNDATIONS AND SUPPORTS

A. The contractor shall provide concrete pedestals, anchor bolts, hangers,

channels, saddles, etc., for installation of equipment and apparatus shown on the
drawings and specified in the various sections.

3.3 EQUIPMENT ERECTION

A. All electrical equipment shall be installed in accordance with the manufacturer's

recommendations, good electrical engineering practice, and the relevant
drawings and specifications.

B. All metal surfaces to be bolted shall be thoroughly cleaned before assembly.

The connections shall be tightened with manual torque wrenches to the
manufacturer's erection instructions. Ground equipment according to Section
16452 – GROUNDING.

C. Splices shall be implemented to ensure the electrical continuity of the horizontal

busbars, auxiliary buses and the proactive conductor between adjacent sections.

D. It shall be possible to secure the sections to a floor that is flat by anchoring

directly to a concrete floor using anchor bolts or by securing to ordinary metal
profiles.

3.3 EQUIPMENT TESTING AND COMMISSIONING

A. After the installation is complete and properly adjusted, the contractor shall
conduct operating tests. The various equipment and systems shall be
demonstrated to operate in accordance with the requirements of the contract
documents. Tests shall be performed in the presence of the Engineer. The
contractor shall provide electric power, instruments and personnel necessary for
performing the various tests.
Project No: CUIZ - MC - 001 Dry-Type Transformers
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PROJECT: The Medical Complex ‫ المنطقة االستثمارية لجامعة القاهر‬- ‫ المجمع الطبي‬:‫المشروع‬
The Investment Zone of Cairo University - Sixth of October City ‫بمدينة السادس من اكتوبر‬
STAGE 3 – Issue For Tender Stage ‫المرحلة الثالثة – مرحلة العطاءات‬

B. The testing of all electrical equipment shall include, but not be limited to, the
items below. This shall be in addition to testing specified elsewhere in this
specification.
1. General equipment check.
2. Field wiring and ground system verification.
3. Equipment adjustment.

END OF SECTION

Project No: CUIZ - MC - 001 Dry-Type Transformers

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