T
T.M.Haja Sahib
Guest
The American Electrician Hand book states the kva of the transformer should equal the h.p of the motor it is powering to keep the voltage drop within acceptable limits.So if the capacity of transformer were 30kva instead of 25 kva for case below it would have lasted far longer than 4 years.When you have only one 10 Hp motor on a 10kVA transformer you usually have horrible voltage drop problems unless the motor is the only load.
I had an irrigation pumphouse with 3x 10HP running off a 200A single phase service. They replaced a single 10HP, but nobody at the time noticed the pole pig was only 10kVA. Didn't last long before it went boom... The utility was going to replace it with another 10kVA, but I begged for something bigger and got a 25 kVA. Not ideal but it's survived 4 years.
Last edited: