Drawing No: TP-0-ETE-TP-EG-74-503 Rev-A

TP-0-ETE-TP-95-501 and TP-0-ETE-TP-95-502

Name: Transformer Technical Specification for GSUT TP-0-ETE-TP-EG-74-503)

Comments:

1. The Transformers Bushing length must be Considered Level-4 (Very Heavy) Category that is Creepage distance 44 MM/KV , Because our site is very near to the sea (salt accumulation) and old power plants-6 nos are still in working condition (Smoke Carbon) .In preliminary bushing drawing showing the Creepage Distance is 19135mm . But Required Creep age Distance is 22176 MM.Formula Cree.Dist= 44MM/KV x 420KVx1.2(Kdia)=22176MMKd-1.2 (Above 500mm Dia) Refer IEC-60815-1986 Section 6 Page no-17 Bushing CD shall be considered.But As per Contract Document 25240-000-MRA-ETP1-00001 Volume 3G –Material Requesition of Power Transformer section -18.0 Bushing Creepage Distance is 44MM/KV (L-L Voltage) 2. Manufacture to be given the Winding (BIL)Lighting Impulse Guaranteed valve(1300KV) as per our Design Specification 25240-000-3DR-E04G-00001 Rev-2 Class 2.9 page - 19.3. The manufacturer shall be maintained the Dew point at erection time by Hot air dryer. (Humidity shall Be Maintain below 0.7% and If above 2% drying should be performed)4. In Tr. Oil test report shall be added the oil dissipation factor, Neutralization value, Inter Facial Value as per IEC-60422.

Name: Transformer Test Plan and Procedure (TP-0-ETE-TP-95-501 and TP-0-ETE-TP-95-502)

Comments:

1. Separate source With stand they cannot apply 230KV to each winding. Because GSU natural Bushing rating is 145KV.There for Manufacture shall be arranged the standby 245KV Bushing for this exam .

2. As per Our Technical Specification -3SS-ETP1-00901.Rev-000 and25240-000-MRA-ETP1-00001 Volume 3G –Material Requesition of Power Transformer, Manufacture shall be added the below test .

a)Short Circuit Capability Calculation or Short Circuit With stand Test.

b) Impulse Test on Neutral Terminals .

c)Dielectric type& Special Test.