I noticed that when my compressor kicks in I see a glitch on my ammeter even though they are on separate circuit breakers. My question is would a Isolation Transformer help the situation? I tried a Variac but that did not work.
No. This is voltage sag caused by the in-rush current of the air compressor affecting other branch circuits upstream from that breaker. Here are some suggestions to mitigate the issue:
- For the branch circuit the air compressor is plugged into, relocate the breaker in the panel closer to the main breaker.
- Be sure the compressor is on a branch circuit that isn’t moderately used.
- Don’t use the compressor on a 15 amp (14 AWG) branch circuit. The further the compressor is from the panel (the longer the branch circuit conductors), the more important the thickness of the conductor is. Bigger is better (12 AWG is better than 14 AWG).
- If supported, rewire the compressor motor for 240v and move it to a dedicated 240v branch circuit supplied from your panel.
- Get a beefy UPS for the laser, one that can compensate for the sag when it occurs.
- Add a hard start cap to the compressor motor. These are specialized starting capacitors that essentially remove themselves from the circuit upon the motor starting, but before the motor starts they are present to help with momentarily supplying the current needed for the motor’s in-rush draw. I have never seen one used on an air compressor, but why not?
Or, charge your compressor before you start and then turn it off.
Would not have enough air if I turned it off. I was thinking of a UPS also so I’ll try that, a 800 watt should work.
If the compressor is of age, you may also consider if it could benefit from replacing the existing starting cap. Just keep in mind that some motors have a starting capacitor and a running capacitor (2 individual caps). Your HVAC’s condenser, for example, often has this scenario with two caps.
While the starting capacitor assists by supplying a momentary flood of current (very close to the appliance), a motor running capacitor is specific to the design of the motor and windings.
My point is, if you decide to change out or upgrade a capacitor on the compressor motor, confirm it is the starting cap.
Basic Info here:
(or just get a UPS 
)
It is a new compressor. I just got this https://www.amazon.com/gp/product/B084T67V7V/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
I was thinking about putting one of my UPS on my laser (but for mitigating a quick power outage). But what I realized is that I’d have to be able to support the laser, 5200 chiller, and extractor. So I just rely on Ruida’s ability to restart a job where it left off in the event of a power outage.
But for your purpose, smoothing out a sag to the laser PSU, I hope it works well. Please let us know.
Here’s my UPS I considered using:
Hi, try a soft start module for the compressor
It has a soft start on the compressor.
It didn’t work!
Please tell me : what didn’t work ?
Maybe it is a solution if you change the compressor ?
I am using a Thomas Compressor/Vakuum Pump like that https://www.ebay.de/itm/Thomas-Kompressor-2450AUU/282047909945?hash=item41ab5d9039:g:6wYAAOSw3KFWg~wV
It is very silent, air enough, without oil and i switch it over a SSrelay directly from the Trocen DSP
Greets
Hartmut
Late to this thread, but anything with a motor will destroy a UPS. Large UPS + Small motor = “may not notice”, but bad things will still be happening.
The UPS wasn’t for the compressor… it was for the laser.
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