Battery Charger Transformer Question

[Windmill1]

Hello,
Can anyone tell me if a forklift battery charger that the tag on charger reads, Input 208,240,480 volts, Is it possible to wire this transformer inside the charger to operate on 220 volts. I cannot find a charger to charge the 750 amp hr, 48 volt  forklift batteries that I may or may not buy.
Any input would be helpful.
Thanks to all.

[Bruce S]

Generally , if you have a setting for 240Vac you can plug the 220Vac directly into it, provided of course the Hz matches.

[Windmill1]

Thanks Bruce
I have been looking at battery chargers on ebay, most all are 3 phase and most are marked 208,240,480.So l  could run any of these chargers off of 220 power from the generator, providing the hertz is the same.
Very helpful.

[dnix71]

Please get a volt meter and check your genset first.

208 is 3-phase in the US and is used in business and light commerce. 240 is split-phase household. Stay away from 480. That's touch it and die voltage used in the US as an intermediate between the 21kv line on the pole to power bus stop and parking lot lighting.

220v is single line hot European voltage used in homes and light commerce.

3-phase can be Y or delta. http://en.wikipedia.org/wiki/Three-phase_electric_power

If your genset is over 5KW nameplate and has 2 hot wires then it supplies split-phase 240v for the usual US household connection. If your genset has 3 hot wires then it is 3-phase like the chargers you were looking at. 220v 3-phase is used for high current European appliances.

Big lift battery chargers for flooded cells are usually ferroresonant. If you do not supply the correct voltage and freq they will not charge correctly but may appear to be working. We had a lift charger at work with 208v connected to the charger's 240v lead. It would appear to charge and finish but the battery was still half-dead. We thought it was the battery until the service tech opened the charger cover to check connections.

European frequency is 50Hz. The US is 60Hz. That needs to match or you will have to derate the charger quite a bit.

[Windmill1]

Thank you
Very well explained.
Many thanks to all

[Frank S]

Since your charger  obviously has a multi tap transformer in it Like "dinx71" said you (a) need a multimeter and (b)you will have open the charger up to determine which taps the power input is connected to.
 A lot of people call their house voltage 220v this is a throw back to the days when the split phase voltages was actually 110vac, in some rural areas of the US this can still be the case. Just like in Europe and particularly in the more developed parts of the middle east much of the voltage is now 230v.
 A lot of industrial buildings still have 440v labels on their disconnect boxes when they actually have 480v
 you can find labels of 440, 460, 480, just about anywhere and in Europe you might see 380, 400 and 415v

[Flux]

I suspect these are just nominal voltages. More important is frequency.

If it is a N American charger designed for 60 Hz it will be most unhappy on the same voltage at 50 Hz. If it is European and intended for 50 Hz it will most likely not object to 60Hz.

Another thing is that you seem to be running it on a generator, so much depends on the generator and the charger design that this may have more impact than the exact voltage.

Basic simple battery chargers with transformer, rectifier and a bit of resistive ballast often work very badly on small generators. The generator  reactance is so high that they can't hold up on the peak when the diodes conduct. Those chargers with power factor rectifiers or a big choke after the rectifier work much better as the current draw is extended over the input cycle.

Flux

[Flux]

Having just read through your posts again, make sure you don't try to use a 3 phase charger on single phase. Most of the larger fork lift chargers tend to be 3 phase and special single phase versions are very costly.

I have to admit that those nominal voltages do suggest it is likely to be 3 phase. A 3 phase charger will give little output on single phase on the mains and be even less use on a generator.

Flux

[Windmill1]

Thanks
From all the info all you guys have given me, I was able to get the charger I needed  on ebay. A 48 volt single phase is hard to find. This one charges  up to 100 amps , has equalize and float charge.