Saturday at home, installing an inverter

[Justloadit]

Here a picture of it for those not too interested in reading the brochure

[AndyD]

...........i wouldnt recommend a 1kw at all. if you run these inverters full load all the time it wont last long.........

This was one of the reasons I installed this unit in my home office, I wanted to put it under a test regime before I offered them as an option to customers. I've performed a series of marginal and substantial overload tests under varying ambient temperatures on it whilst monitoring internal component temperatures to see how it performed. I've run it under highly inductive and highly capacitive loads and I've also run some controlled short circuit tests to check disconnect times of OCPD's etc and fault current handling abilities of the output components and internal safety systems.

[bergie]

andy, is it the 1kw axpert inverter you are testing? for blacknights purposes it probably would be under rated

[AndyD]

It's the 3kW unit same as Blacknight was looking at for his installation.

[IMHO]

Andy, need your help!

As you know I run a guesthouse and I am looking at getting away slowly from Eskom. I am changing my geysers to gas as they pack-up. Done two so far, plenty to go. Stove is gas now as well. The next area I need to tackle is my laundry. I used the clamp tester method as you showed and here is the results. I would love to put the laundry on solar. I use the tumble dryers a lot, as it is the only way to get our towels soft. The washing machines also work hard. Ironing is 3 irons for about 2 hours a day, but lets work on 4 hours a day.

Appliance Iron x 3
H/day 4 hours
Amps peak 7.8A
Amps normal 0
They switch on and off, so it is either peak or off, They switch on for a minute or two to get to temp and then switch on and of every few seconds, say 30sec intervals.

Appliance Tumble Dryer1 (10kg)
H/day 4 hours
Amps peak 13A on switch on
Amps normal settles to under 8A
Peak at 13 amp very short. Then stays on 7.8A about for the duration.

Appliance Tumble Dryer2 (5kg)
H/day 2 hours but very seldom uses it. Just on very rare occasions.
Amps peak A on switch on
Amps normal settles to under A
Peak at amp very short. Then stays on A about for the duration.

Appliance Washing Machine Whirlpool
H/day 4 hours (actual 3 but work on 4)
Amps peak 5A on spin
Amps normal settles to under 3A

Appliance SpeedQueen
H/day 4 hours (actual 3 but work on 4)
Amps peak 8A on spin
Amps normal settles to under 5A

My aim would be to get these appliances completely off grid, with solar. So I need to know the inverter size and specs, batt capacity and solar panels to do the charging. Rainy or cloudy days, I will have to revert back to Eskom. Or will it be cost effective to have battery capacity to last 4 days? I would also need something to tell me what capacity is left. (Like a petrol gauge, hehe)

[IMHO]

Another thing to consider. Whasing is done in the mornings and ironing in the afternoon, with tumble drying between washing and Ironing.

Lets say 8am to 10am washing
11am - 1 pm tumble drying
2pm-4pm Ironing.

Above is a tipical day. As you can see, I overstated some durations above. I omitted tumble dryer 2's specs above, as I do not have it. It can be ignored.

[AndyD]

A couple of observations to start with, the washing machine current draws are lower than I would have expected for commercial machines, are they being supplied with pre-heated water? If they're heating their own water I think their maximum load should be higher durng the heating cycle than during the spin cycle.

Secondly the tumble dryer with it's short peak of 13A,is this the motor start current or is the duration of this peak longer than a second or two?

Also can you define the overlap between the washing and drying and ironing where two of the operations are taking place simultaneously or even all three operations?

[IMHO]

are they being supplied with pre-heated water?

No, we wash cold water only. I only measured spin cycle, due to this reason. I can use hot water, but that is supplied via the hot water tap, from the geyser. I will test again when they use the machine again. BTW, it is not commercial machines, it is the normal household big Whirlpool and SpeedQueen machines, +-12kg

Secondly the tumble dryer with it's short peak of 13A, is this the motor start current or is the duration of this peak longer than a second or two?

No, a second or two. If you do not watch closely, you will miss it.

Also can you define the overlap between the washing and drying and ironing where two of the operations are taking place simultaneously or even all three opera

I cross questioned the staff and my wife on this today. Seems like there is no overlapping. Washing is done early morning when they are still cleaning rooms. Then when the tumble drying start, it is to uncomfortable in the room to do ironing. I realize that saves me a lot. I will just have to make it law that there is to be no overlapping, even as an exception, and install an alarm type buzzer that warns when the threshold is reached or tripping out at a safe amp-age cutoff?

[IMHO]

The bulk of the laundry, namely the sheets, is send to someone else to wash and Iron. We do only a little bit of that, if we get our planning wrong. Our biggest loads is towels and pillow cases, plus clothing.

PS. I have just been informed we do a fair amount of sheets ourselves now as well, as the laundry in town can not keep up. But we stick to the hours mentioned.

[bergie]

i think the top loaders should all have a separate hot water connection and the front loaders have a built in element,with no hot water connection. i speak under correction.