Has anyone any ideas on using a Transformer (1kVA) the wrong way round. The transformer has a 230VAC primary and a 110VAC secondary. Would it be OK to use the secondary as the input(110VAC) and put the load on the primary - a 230VAC motor. Only need about 250Watts. Will it work? Michael.
Normally I would say yes, if it were 240/480 volt. But I am not sure with 120 volt. You only have one CCC and a neutral. But I think you are okay. Protect XFMR on line side as current is less. I have never back fed a 120/240 volt XFMR, so I am not sure about the neutral.
J Valdez: At "110" Volts you will have 2 current carrying conductors...both the ungrounded conductor and the grounded conductor are current carrying.
The current on the line side will be MORE than the current on the load side. The OP never said this is a 120/240 transformer, rather a 230 to 110 transformer.
We used a "backward" transformer in our shop for many years. I had a 240v blower motor out of a tape drive we used for shop air on the 120v they supplied us using a convenience outlet transformer, usually providing 120 out of the 240 in the computer room.
No. Use a seperate BONDING conductor to "ground" the secondary enclosure. Note that the 120 primary will draw 2+ the amps of the secondary load. Ohms Law.....Obey it. God doesn't give tickets.
Alan-- If it was easy, anyone could do it.
#170748 - 11/10/0706:24 PMRe: wrong way Transformer
[Re: MMK]
We discussed this before. If the transformer is part of the building wiring you need to ground the secondary, with few exceptions. If it is a cord and plug connected appliance you don't. (that was where I went wronmg the last time it was discussed) It is very common that a lab work bench supply is flaoting but this is a cord and plug cionnected appliance, not building wiring. We had the same situation with our compressor at the shop. The whole assembly was behind a 5-15 plug.
