Shop Voltage Limits for Edgebanders

Accurately controlled AC voltage supplied to the machine is important for regulating the 24-volt DC output of the edgebander's internal transformer. October 15, 2009

We just received a new-to-us edgebander. Tech says we need shop voltage to be close to 230, but no more than 242. I checked our lines with 3 different meters and got 225, 243 and 248. Teck says 248 is too high and we need to add a buck boost transformer to step down to 230. Should I check with a fourth meter (maybe more accurate), order the transformers, or figure it's close enough since it's supposedly 230 according to the power company?

Forum Responses
(Dust Collection and Safety Equipment Forum)
From contributor D:
What the tech is actually concerned with is the 24V DC control voltage that is generated inside the machine. Most machines will have a 24V DC transformer inside the machine to convert the AC voltage to DC to operate the controls and switch circuitry inside the machine. If your AC voltage is too high then your DC voltage will likely be too high, since the transformer is designed to step the voltage down a certain amount. Sometimes machines will run normally with a high DC voltage and sometimes they don't. However, it is more likely to cause damage to components over the long term if your DC voltage is high.

If you bought a high quality used bander with low miles and long term expectations, then I would consider a transformer - that is, if your voltage is actually too high. Voltages do vary from building to building and the power company will not take any liability for your machinery. If your technician was on site, then he should have had a high quality voltage meter and should be able to get an accurate reading.

From the original questioner:
Thanks for the response. The tech is coming from out of town on the 29th to do the install so he has not checked it yet. The bander is a 2005 model so we don't want to mess it up. Think I will try to find a more accurate meter.

From contributor R:
With a newer style bander such as yours and with any high tech equipment, keeping the power within 5% of name plate voltage is advisable. Some areas have real high voltage because they are very close to a transformer and the power company usually has it higher to make up for voltage drop.

I do not like buck boost transformers at all. Yes, they work, but nowadays you can pay about a grand and get a constant voltage regulator that will boost or reduce your incoming voltage to the exact output voltage you need. I believe they have a +/- range of 10%. Grainger sells them.