I have a new piece of equipment I'm powering up, and the incoming voltage is too high. The equipment's rating is 220VAC +/- 10%, and the incoming single phase voltage is 245VAC. So I've landed on using a buck-boost transformer to knock down the voltage.
After looking through various sites, I landed on needing a 1.3KVA rated transformer (24VAC x 55A = 1.3KVA) to go from 245VAC to ~220VAC. I ordered a step down transformer from McMaster(McMaster-Carr) as it says it is rated at 1.5KVA at the required input / output voltages. The nameplate KVA rating is 0.15KVA, though I understand because the primary and secondary windings are tied together for buck-boost operation (autotransformer), the ampacity increases. This transformer (ACME electric) weighs roughly 15 lbs.
After double checking a few other sites using their calculators, the recommended transformer is a 1.5KVA rated, weighing in at ~30 lbs. This is a calculator provided by ACME electric for the given input, required voltage drop, and load (55A).
Is the transformer I purchased through McMaster adequate, or are the ratings they provide bogus? Perhaps the ACME-recommended 30 lb transformer is isolated, whereas the one purchased through McMaster is not?
Thanks,
Ben
After looking through various sites, I landed on needing a 1.3KVA rated transformer (24VAC x 55A = 1.3KVA) to go from 245VAC to ~220VAC. I ordered a step down transformer from McMaster(McMaster-Carr) as it says it is rated at 1.5KVA at the required input / output voltages. The nameplate KVA rating is 0.15KVA, though I understand because the primary and secondary windings are tied together for buck-boost operation (autotransformer), the ampacity increases. This transformer (ACME electric) weighs roughly 15 lbs.
After double checking a few other sites using their calculators, the recommended transformer is a 1.5KVA rated, weighing in at ~30 lbs. This is a calculator provided by ACME electric for the given input, required voltage drop, and load (55A).
Is the transformer I purchased through McMaster adequate, or are the ratings they provide bogus? Perhaps the ACME-recommended 30 lb transformer is isolated, whereas the one purchased through McMaster is not?
Thanks,
Ben
Last edited: