[How do I?] Get 3 phase

[tq60]

What is duty cycle of charger?

If you are running full shift and need lots of charge get a new charger, they show up, sold ours for 100 bucks or so.

If only minimal use then look at a golf cr charger.

Can get 5 Amp unit for 40 bucks on Amazon.

We have one that we have Anderson connectors on, use it to charge golf car ND fork lift.

Many options.

Check forklift dealers, may be able to trade in.

Sent from my SM-G781V using Tapatalk

 

[MikeInOr]

It should run on 240 volts single phase also, it will just take a bit longer to charge. Just connect the power to two of the 3 input terminals.
-M

A 3ph battery charger will run through a 3ph rectifier to produce the needed DC current. You can use 2 of the 3 leads going into the rectifier to run it on single phase and it should work just fine.


Like this diagram shows there are just 2 extra diodes in a 3 phase rectifier. If you don't use the third leg (so you won't use the extra 2 diodes) it is in essence a single phase rectifier.



Just use two of the 3 phase wires in the plug and the ground and wire them to a 220v plug ignoring the 3rd power leg.

Just like Mark said!

 

[rabler]

The problem with "just running it on single phase" is that it is basically an AC to DC converter. It is going to attempt to deliver the current needed to reach a certain voltage, and it will draw that current through the single phase instead of across three phases. Think about a simple transformer-capacitor supply. With two phases missing it is going to try to charge up the capacitor only 1/3 as often. In the mean time the capacitor is going to have three times as long to discharge, and therefore draw significantly more current on that single phase to recharge (with greater voltage ripple).

A switching supply will have some to the same issues, just more complicated dynamics. Similar logic as why VFDs have to be oversized to run off of single phase.

 

[MikeInOr]

The problem with "just running it on single phase" is that it is basically an AC to DC converter. It is going to attempt to deliver the current needed to reach a certain voltage, and it will draw that current through the single phase instead of across three phases. Think about a simple transformer-capacitor supply. With two phases missing it is going to try to charge up the capacitor only 1/3 as often. In the mean time the capacitor is going to have three times as long to discharge, and therefore draw significantly more current on that single phase to recharge (with greater voltage ripple).

A switching supply will have some to the same issues, just more complicated dynamics. Similar logic as why VFDs have to be oversized to run off of single phase.

True but you are only missing 1/3rd of the power, not 2/3rds of the power. So each single phase leg will be pulling 1/3 more current through it than it would with 3ph power. Most all rectifiers are overrated and have a pretty good buffer for the current they will carry. I have a friend that runs his 3ph Miller welder on single phase. Yes, at peak draw it will pull more current through the 2 hot legs than if he had the third hot leg of 3 phase power.

You are using 4 of the 6 diodes of the 3ph rectifier when you use it on single phase instead of 3ph.

 

[rabler]

The conversion is sqrt(3) for current to deliver the same power (i.e. charge as fast). I didn’t say it would draw 3 times the current or 3 times the power. I said you have 120 half-wave cycles vs. 360 half wave cycles. Yes, 6 diodes gives 3 separate full wave rectified sine waves.

You get a voltage decay based on e^(-t/rc) for a linear (resistive) load. So three times farther down a logarithmic decay for throwing out 4 of the 6 half-waves. A battery is a nonlinear load. Ideal battery charging is not simple. Be interesting to see if higher ripple affected battery life. Fire-prone lithium batteries anyone?

Hard to speculate what other behaviors are designed into the charging circuit. It may work, may not. Be an interesting *experiment*. My guess is it works but tends to run hotter, shortening the charger life span. A completely dead battery would be the stress test. But it is not a completely trivial “yes this will work”.

 

[Cadillac]

First thanks for the responses. Ive Been super busy getting the new warehouse ready. Lots of cleaning and painting Amongst other things. Finally getting around to the forklift charger. I took a video of the internals. To give a better view of what I’m dealing with. the wife called her forklift guy and he did he’s got the word out for one but doesn’t have one on hand. And she didn’t get a price.
She uses the forklift but not for every job. She would be able to operate fine with a longer charge time. Any thoughts would be much appreciated thanks. i couldn’t upload the video but I did take acouple pics.

 

[Cadillac]

Just alittle update to the post. I ended up going the route of replacing the charger with a dedicated 1phase unit.
Our forklift rep ended up lending us a 1/3phase charger that will charge 24,36,48 depending on what leads you have connected. This will get us by till the new one comes. A week they said.
Found a surplus charger from a outfit out of Ohio. Matched all my specs and luckily they had one in stock ready to ship. Shipping a 300* charger two states was surprisingly cheaper than I thought. 150 bucks not bad for the weight.
Just wanted to say thanks again for all the help you guys gave me.