FYI info on Mitsubishi Mini split system

I have a multi unit 3 Ton system with 3 inside units. It is a heat pump (no heating strip, no defrost heat strip).
A few things I found was it…

  1. It was very hard to detect or measure until I put it on a Dedicated Circuit.
  2. It seems to consume more power in heat mode than cool. Not sure why. Winters are usually mild here. Summers, not so much.
  3. Latest thing I discovered is its power consumption when “off”. I knew it used some power but was surprised to learn how much of a vampire it can be.

I recently had mild weather and turned off all the inside units for over 24Hrs. Below is snapshots of its usage. I knew of the low 7 watt but was surprised to find it “cycles” about every 30 minutes to a 60+ watt “cycle” for about 15 minutes. Why? I have no idea but found it interesting and figured I’d share the info.

The outside unit is hardwired to the breaker panel so it is never truly OFF.

1 Like

@ron111157, really interesting data and assessment. I can add to the Community Device Library if you give me a little extra information…

Here’s the info required.

Make: Your make
Model: Your model
How identified: How it was identified (Sense Identification, Smart plug, Manual, DCM)

Additional Comments:
Power Specs: Power specs or link to product information
Operating Wattages: Various wattages at different stages of operating (i.e. “Standby”, “On”)

@kevin1 Sure. No Problem

Make: Mitsubishi Mini-split Multi Unit.
Model: Outdoor Unit MXZ-4C36na, Indoor unit X3 MSZ-GL12na-u1
How identified: DCM

Power Specs: Power Supply Voltage, Phase, Hertz 208 / 230V, 1-Phase, 60 Hz
Recommended Fuse/Breaker Size A 25
MCA A 22.1
Operating Wattages: Constantly varies. Typical average 700-1200w. Total usage in Feb. was 346.8 kWh

Did some additional reading on here about Heat pump Mini-splits and it could be what they call a pre-heat control. It may be this.