Arkansas HVACR NewsMagazine September 2021

HVACR NewsMagazine September 2021

Tech News

maximum potential between the points is lower overall. You can see this in the image below.

230/208v also have a harder time starting up, and they may produce a problematic voltage drop more often when connected to 208v. Voltage drop usually isn’t an issue for split -phase 240v systems. However, on 208v, the motors start with lower voltage. Therefore, the same amount of drop will have a greater effect on the system. In short, just because a 208v motor may be designed to run on 230v or 240v systems by using two power legs from the utility source, that doesn’t mean that it will provide the same output efficiency. You will see differences in performance if you try to use 208v when 240v is typically required.

Can you use 208v motors instead of 230v/240v?

You may notice that some single-phase motors are rated for 208/230v. So, it may seem as though the motor will find ways to make up for the lower voltage. That’s not quite how these motors work. You’ll see some differences in performance if you use a 230v motor for a 208v application, even if it’s rated for both. You can’t expect the same degree of performance when you use 208v on 230v (or higher) applications. For example, when you use a 208v motor in a residential condensing unit that typically requires 230v, the unit won’t run at its full capacity. Some people say that you can expect a higher current when you use 208v in place of 230v, but th at’s quite rare. The motors don’t magically makeup in current what is lost in voltage, even if it might make sense to see higher current from the rated watts or horsepower. Instead, when a typical 208/230v motor is connected to 208v, it usually slips more and runs at a lower output than on 230v or 240v. This results in lower wattage used at a lower efficiency, which adds up to few BTUs produced.

Emily Gutowski is a regular contributor to the HVAC School founded by Bryan Orr.

Bryan Orr, HVAC School ( Founder / Podcaster / Dad of 10 ) Bryan Orr is a lifelong learner, proud technician and advocate for the HVAC/R Trade

The NewsMagazine is grateful for them generously sharing the information with you and encourages you to subscribe to Brian’s web page. Click on the following picture to link to the site.

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