Hard Start Relay Capacitor

islandguyislandguy ✭✭✭✭Solar Expert Posts: 80 ✭✭✭✭
A couple of years ago I purchased a small electric fridge to use in my off-grid set up. Electric, SPT model RF-322SS.

I also use the effergy engage platform to track my energy usage. About a year ago I notice random 100 or 200 watt spikes when the fridge started it's cycle. Using the efergy's graphing ability I can tell that the fridge comes on about once an hour for about five minutes and draws around sixty watts.

Since the large watt spikes were getting worse I thought I'd try a capacitor. Picked up a SUPCO HS6 from Amazon for around twelve bucks. This unit smoothed out the starting surges. Reading the comments people are using these to help run air compressors and AC units off grid.

if anyone else is looking for a simple quick fix to small motor starting loads, this seems to work well.

Comments

  • CariboocootCariboocoot ✭✭ Banned Posts: 17,615 ✭✭
    Re: Hard Start Relay Capacitor

    Keep in mind that one capacitor will not work for every motor. At least not optimally.
  • islandguyislandguy ✭✭✭✭ Solar Expert Posts: 80 ✭✭✭✭
    Re: Hard Start Relay Capacitor

    thanks Cariboocoot.

    Actually, two things.

    1st I came across some good threads on this topic over in the energy use and conservation section. Very informative, and a good thing because -

    2nd thing, the reason I wasn't getting any more power spikes on my graph was because the fridge compressor did not start up.

    I'll try wiring it differently. If I get it working I'll just add the info to the proper threads.
  • CariboocootCariboocoot ✭✭ Banned Posts: 17,615 ✭✭
    Re: Hard Start Relay Capacitor
    islandguy wrote: »
    thanks Cariboocoot.

    Actually, two things.

    1st I came across some good threads on this topic over in the energy use and conservation section. Very informative, and a good thing because -

    2nd thing, the reason I wasn't getting any more power spikes on my graph was because the fridge compressor did not start up.

    I'll try wiring it differently. If I get it working I'll just add the info to the proper threads.

    Normally a start capacitor is just on the starting windings, not on the AC input to the motor. This is not always easy to achieve especially on the newer all-in-one sealed motor-compressors.
  • Ks SolarKs Solar ✭✭ Solar Expert Posts: 47 ✭✭
    Re: Hard Start Relay Capacitor

    This is interesting. Just today a HVAC guy added one to my mother in laws unit. It dropped the inrush from 38 a to 11 amps. The original cap checked good and is still inline as well.
  • MangasMangas ✭✭✭✭ Solar Expert Posts: 547 ✭✭✭✭
    Re: Hard Start Relay Capacitor

    Nine years ago, we installed motor run caps to our off grid central HVAC system (two split 3 ton furnace and A/C units). When initially installed the new system was running erratically and periodically locking out.

    Since the $25 caps were installed the HVAC hasn't missed a beat in 9 years running smoothly and reliably.

    Going on ten years, we're in the process of installing two new modulating variable speed furnaces and two 3 ton A/C compressors. The new units are rated 21 SEER and up to 97% AFUE. We hope they will use less energy than the old 18 SEER and 80% AFUE units they are replacing.

    Be interesting if they are able to free up some battery storage.
    Ranch Off Grid System & Custom Home: 2 x pair stacked Schneider XW 5548+ Plus inverters (4), 2 x Schneider MPPT 80-600 Charge Controllers, 2 Xanbus AGS Generator Start and Air Extraction System Controllers, 64 Trojan L16 REB 6v 375 AH Flooded Cel Batteries w/Water Miser Caps, 44 x 185 Sharp Solar Panels, Cummins Onan RS20 KW Propane Water Cooled Genset, ICF House Construction, all appliances, Central A/C, 2 x High Efficiency Variable Speed three ton Central A/C 220v compressors, 2 x Propane furnaces, 2 x Variable Speed Air Handlers, 2 x HD WiFi HVAC Zoned System Controllers
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