Inverters

[homesman]

I have bought a 1/2hp 90vac 1ph motor on ebay. My need is to convert 12vdc to the 90vac, but am having trouble fining a inverter that will invert to 90. Will a inverter that does invert to 110vac work with this 90vac, or do I need to send this motor back?

 

[Hopup]

You can reduce the voltage using variac. They are widely available on Ebay and other sites.

 

[duke37]

A 20V transformer can be used to subtract 20V from the invertor output.
The motor may not like a non sine supply. What does your invertor supply?

 

[flippineck]

Watch out as well for the cheaper inverters that claim a certain power rating but fail to deliver it for a number of reasons.

I bought one from a Chinese Ebay supplier that claimed '3000W / 6000W peak' but in practise it only seems to be able to reliably cope with much less. Connecting a 2400W kettle causes it to go into instant overload protection. I only use it to run the LED lighting in my caravan now. I resorted to a diesel generator for the kettle etc.

I understand many types of load classed as 'inductive' (some motors, fluorescent tube ballasts etc) take a much higher current than normal for a few seconds on start-up, such that you might need an inverter with a rating much, much higher than the appliance's normal constant running rating in order to get it started reliably.

I might be wrong but I think there's a technology called 'soft start' on some inverters that tries to cope with inductive loads by slowly ramping up the output on load connection, so there isn't so bad of a sudden current rush

 

[JWHassler]

Where did you get a 90 volt AC motor?
Ninety volts DC is very common