Lets discuss inverters......

[Industrial Toys]

A compressor could use maybe five times the normal running current on start up, if I am not mistaken.

 

[5030]

I have a 12 V cable for mine that came from the manufacturer, as I recall it was about $40. It will plug into a standard 12V accessory plug or clip directly to the battery posts. A deep cycle battery provided at least a weeks worth of 8 hour nights.

I'll have to check that out. Not sure mine does have that capability.

 

[5030]

This thread has me wondering if my Heat Pump can safely operate off of the power from my 7KW alternator generator, maybe I should dedicate it to that and get an inverter generator for the electronics, lights etc. that share the same circuits.

Then just keep a bucket of ice in the freezer and toss that in the refrigerator when the power goes out to keep the beer cold.

One of my hunting buds just built a new home (3 bedroom open floor plan ranch on a crawl) and his heat pimp installer recommended a 17KW, which he just had installed. I have a 17KW myself and it don't run everything, almost, not quite. 7KW ain't much. (7000 watts give or take). The resistance heat elements in your heat pump if they came on, would bury 7KW.

 

[5030]

A compressor could use maybe five times the normal running current on start up, if I am not mistaken.

On 240, starting (inrush) amps are 3 times running amps on a capacitor start induction run compressor motor. I have a 7.5 horse in my shop and I've had the clamp on amprobe on it. It pulls pretty hard, almost 28 amps on each leg starting and about 10-12 running, depending on static pressure on the compressor head. The higher the head pressure gets the more amps it pulls.

 

[TomSeller]

One of my hunting buds just built a new home (3 bedroom open floor plan ranch on a crawl) and his heat pimp installer recommended a 17KW, which he just had installed. I have a 17KW myself and it don't run everything, almost, not quite. 7KW ain't much. (7000 watts give or take). The resistance heat elements in your heat pump if they came on, would bury 7KW.

I don't have resistance heat, I have to use wood heat when it gets cold.

 

[5030]

I have no idea what kind of motor is in the CPAP, I know it has a motor, a small one. I have to presume it's some type of vane compressor, not a reciprocating compressor because the sound it makes is steady. never had it apart.

They seem to last a long time. I still use my original CPAP that I got over 20 years ago, every night. It's an old Resperonics. I think, last time I checked, it had over 28,000 hours on it and still running strong....

Of course it's about 4 rimes as large as my newest one.

 

[Industrial Toys]

I can almost hear the inverter transistors going "snap, crackle and pop" in cascading fashion as they do.

A generator has the rotor momentum to provide additional motor starting power. An inverter has no such facility unless it is very, very under loaded.

 

[SPYDERLK]

On 240, starting (inrush) amps are 3 times running amps on a capacitor start induction run compressor motor. I have a 7.5 horse in my shop and I've had the clamp on amprobe on it. It pulls pretty hard, almost 28 amps on each leg starting and about 10-12 running, depending on static pressure on the compressor head. The higher the head pressure gets the more amps it pulls.

,,,,,,,,,,,,:confused2:

You have 3 phase power? ... Thats the only way those numbers could be anywhere close to accurate.

 

[Industrial Toys]

I'm not sure why starting to running current ratio would have anything to do with voltage. A 110V single phase motor could also draw three or whatever times as much current on startup. My 2 HP 110v pressure washer motor draws piles of current on startup and it's hard to find a 15 amp circuit that will run it.

 

[Wood_Butcher_Dav]

I have used a single battery with an 750W schumacher inverter for 4 nights in a row and only dropped a 1/2 volt, don't use the humidifier. The CPAP that i take camping is an older backup and is a Rem Star brand.

Dave