Overcurrent protection 45 kva transformer | Information by …
2019年4月12日 · Blue prints requires a 100 amp 3 phase 120/208 panel. Blueprint has no detail to feeder size and wire sizes. i know i can feed a 45 kva with 480 3 phase and a 70 amp breaker and get 125 amps secondary. So the secondary panel has a 100 amp main breaker . I fed a 45 kva transformer with #6 thwn...
Sizing conductors and overcurrent protection on both the primary …
2021年4月29日 · Most projects are engineered for me but I have a specific piece of equipment that I am trying to connect a 208 3 phase to a 45 KVA transformer which is a step up to a 60 amp piece of equipment that is 480-volt. I am struggling trying to determine what size overcurrent protection I need on the...
45 kva to 75 kva transformer - keep the same primary feeders
2021年3月10日 · 3 phase 480V -- 60A breaker -- #6 THHN feeding 45 kva 480v delta 120/208 wye transformer -- secondary feeds 125A breaker disconnect. Customer is requesting that we: Keep the same primary (cost savings). 60A breaker with #6 feeders to a 75 kva transformer. The secondary will then feed a 150A breaker disconnect with 1/0 conductors.
45 kVA transformer primary OCPD & conductor
2022年10月21日 · In Mike's recent article, he has an example with 45 kVA transformer 480V primary and calculates a 70A CB for the primary with #6s. Question, 45 kVA 480V primary = 54.12A x 1.25 = 68A, round up and you have 70A OCPD. But how are #6's (rated 65A) OK? Assuming max load 54A and continuous load...
45 KVA transformer max amperage? | Information by Electrical ...
2014年11月18日 · What matters is only the total KVA of the loads. If your mission is to match a transformer size to the rating of a 200 amp panel, you get there by multiplying 200 amps times 208 volts times 1.732. That result is 72 KVA. Even if you allow for the short time overloading of a 45 kva transformer to a level of 125%, it would still only give you 56 KVA.
45kva transformer | Information by Electrical Professionals for ...
2022年6月25日 · Hello I have a 45kva transformer. Delta to wye. Sizing the primary and secondary conductors the engineer is calling for: Primary: 4awg and 70amp ocpd Secondary: 1/0awg and 150 ocpd Shouldn’t the secondary conductors be 2/0 awd if: 45000/208x1.73 Furthermore does derating at 80%...
Sizing conductors and overcurrent protection on both the primary …
2021年4月29日 · There are tricks for energizing transformers on breakers that are 'too small', but they require control circuits to 'precharge' the transformer through a resistor while the secondary load is disconnected, before you get to that stage you …
45kva transformer OCPD question | Information by Electrical ...
2015年8月17日 · I have a 45kva 480v to 208/120v 3ø transformer that is suppliedby a 150amp existing breaker. The 45kva transformer in turn supplies asecondary is a 100amp disconnect that is within 10’ of the transformer 480vac3ø 45kva Primary OCPD (NEC 450.3(b) Primary OCPD at 250%. = 54amp x 2.50 =135amp Next size up is 150amp breaker (NEC240.4(b).
45 KVA transformer max amperage? | Page 2 | Information by …
2014年11月18日 · Does it mean, if properly balanced a 45 kVA three-phase transformer can supply a whopping 375 Amps at 120 volts ? This will affect the panel size I choose. This is a lot of current for a relatively small transformer.
45 KV Transformer Feeding 200 amp panel? | Information by …
2007年1月16日 · 45 * 1000 = 45,000 watts / 208 = 216 / 1.73 = 125 amps of capacity. Are you sure it's a good idea to supply a 200 amp panel with a transformer that only has 125 amps of capacity? You could.....if there is a 125 amp breaker between the transformer and the panel and as long as the calculated load is under 125 amps.