What warranty? You're on renewable energy

[wpowokal]

We installed a second hand cool room 3mX 3m

(10'X10') the old condensing unit used R12

refrigerant that is no longer available and was

 belt coupled, therefore in the interests of

efficiency we installed a new unit, and so the

troubles began.

Our inverter is a Solar Energy Australia

SEAP-24-3K0, a pure sine wave 24v 3 kW

continuous, 4 kW for 10 min, 3.8 kW for

30 min with a 9 kW surge capability. I had every confidence that it was up to the task,

but from the word go the condensing unit overloaded the inverter approximately every third start.

http://www.solaraustralia.com.au/html/everest.htm









A brief explanation of the refrigeration cycle

 for those who are unfamiliar (for the purists

this is not a technical tuition).

In the case of this cool room the refrigeration

 is in two parts, the evaporator is inside the

cool room with its associated fan(s). Part of

 this is the expansion valve, basically an

orifice that drops the refrigerant pressure,

 which dramatically drops its temperature,

 this is the part the cold comes from.

Outside is the compressor and condenser

(radiator), the compressor takes its suction

off the evaporator return, a gas at this stage,

 compresses it to a high pressure. The compressor discharge goes to the condenser

where it is cooled by a fan passing air across the fins and returned to a liquid.  This liquid

 collects in the accumulator and from there to the expansion valve, and so the cycle begins again.

In order to find the reason for the inverter

overloads I began investigating the power

 supply at the source, the batteries. (again for

 the purists all problems could probably have

 been sorted out in about 3 hours of fault

finding, but I live on site and wanted to know

the cause.)

I checked the DC connections, fuse connections,

AC connections at the inverter, distribution

 board, change over switch (this allows me to run the cool room on the generator)

and finally the isolator at the condensing unit. All were sound,

and voltage measurements taken when the unit started correctly showed a drop from 240v to only 238v.

 Instantaneous start amps on the refrigeration guy's

digital tongs (instrument for measuring amps by clamping around a cable)

 showed 39 amps, my analogue tongs showed 25 amps,

 even on those occasions when it would not start.

Run amps for the condensing unit was 4.7 amps.

Next I dived into the junction box on the

unit and two earth wires pulled out of the cheap spade connector

 which was part of the refrigeration guy's installation of the thermostat and high pressure switch. All power

 to the unit passes through these two devices, so I checked and replaced all his other spade connectors for

"proper" ones.

 A test run period showed an improvement but not cure.

So into his other connections on the

thermostat and high-pressure switch, the

 thermostat had connections where the wire is captive under an inverted U onto the flat lug.

 Yep you guessed it one connection was loose because the U was not aligned the other just not tight.

The high-pressure switch had only one loose

 connection. Another test run period revealed there must be more faults.

During this period we were having

relatively high temperatures with many days

 in the high 30's and several over 40 deg.C. The inverter specs say it must be dratted

1.25%p/dc. for temperatures above 30 deg C.

 So thinking the inverter may be overheating I added an old microwave

oven fan

 on top of the heat sink, I also removed a sheet of iron

from the shed to allow more air to circulate, all to no avail.

Now to be fair, refrigeration units need a

period to depressurize after running before a restart. I tossed about ideas about partially blocked

expansion valve, under cooling of condensing unit and raised the

 cut in/out temp difference to 10 deg. but could not hit on anything.

So back into the junction box to check out the condenser

fan and what do you know the spade connector's were crimped on the insulation with the bared cable

splayed in all directions, all leads including the earth. You beauty this could be the answer to the hard starting.









Another test run to no avail,

so back into the

junction box to check all spade connectors, and all others were Ok.

Only one thing left, a blue point connector where the refrigeration guy a had looped the active cable

around the thermostat and HP switch, this he had wrapped in

insulation tape so I had not to this point viewed it.

Undoing the tape revealed the culprit all along, one wire simply slid out,

 he had made no attempt to twist the wires together before

placing them in the connector making a high resistance

connection at this point.

 



Bit fuzzy but look hard and you can see below the black tape one red wire and the bared copper.

Since correcting this, the unit has performed

 well, even started one morning when the toaster was in use(1kW), it is still necessary to maintain

a high differential temperature but that's fine for our purposes.

 Mains, (as the generator can) could maintain the 25 amps required until the

unit started or tripped on

thermal overload, with a lower temperature difference.

To top it all off the refrigeration guy's

parting comment when he presented his bill was "I'm glad you fixed it, I would hate to have

 had to return it for warranty since you are on renewable energy",

 I could have further enlightened him but.....

[RatOmeter]

Do I understand you correctly that this guy did all the wiring, screwed up badly in several places which you fixed, he presented you with the full bill and then had the nerve to say/imply that he wouldn't honor any warranty because you're on RE?

I wouldn't have paid the full bill and I certainly wouldn't allow him anywhere near my electrical circuits again.  His crimp on the insulation in that connector indicates that he's blind, has no understanding of electricity, or no concept of checking his own work.  In short, he is incompetent, whatever the reason.

It doesn't matter even a bit that you're "on RE".  Those wiring mistakes would have brought that equipment to an early death, even (or especially?) if it was grid-powered.  A high resistance connection that is just good enough to let a motor start is even worse/more dangerous than one that won't let it start.  You could go blithely along for a while until your compressor burns out or your building burns down.

Do not trust any other electrical connection he made until you have personally checked them.

Geeze. Let everyone else know that this guy is not to be trusted.

[Volvo farmer]

That blue wire crimp looks awfully factory to me. It takes a pretty special crimper to be able to make crimps like that and I've never seen a serviceman with the tool to do it in his pouch.

It's hard to tell what's going on in the fuzzy picture but I do know for wire-nut connections, The wires are not supposed to be twisted first, The wires are supposed to be placed side by side and the nut is supposed to do all the work when you twist it on.

I'm not sticking up for your installer, he obviously messed up some of the wiring. He should have fixed it and his wiring job has nothing to do with manufacturers warranty, but he has a point about RE and warranty. I had a customer with all sorts of problems running a Kenmore front-loading washer on a Trace SW inverter. Every time I brought it to the shop, I could not duplicate the problem. Finally sent an email to the Homepower magazine folks and they said they had heard of this before and to try a capacitor in line to filter the power. Well that fixed it. My point is that even a "pure" sinewave inverter is not the same thing as a grid sinewave made by moving a magnet past loops of wire. Sometimes electronic devices are affected by the difference and I don't believe the manufacturer should have to warranty that their product will work with any of the dozens of different inverter designs out there.

[old55olds]

I agree with the point that this was probably a factory crimp. I have been trying to get a pair of crimpers for those types of connectors for a while.  Darn expensive. Incedentily manufacturers are expected to cover everything. Short cycling, slugging, oil starvation, oil slugs and on and on. None of it is under the control of the manufacturer. I know of an instance where a deepfreeze was plugged into 100 feet of 18 gauge zip cord and was sent in on warranty several times. And they got it.

ken

[drdongle]

Yes they look like "factory" crimps however they look like the were made wrong, the wire should be striped and held in the middle, these look like the wire was positioned wrong in the criming area.

[wpowokal]

The two crimp lugs were factory connections on the condenser fan, all 4 wires were like this including the earth. I guess the robot had a bad day.

The installer used the same lugs on his wiring and just bent them over with pliers.

Allan

[Drives]

It's hard to tell what's going on in the fuzzy picture but I do know for wire-nut connections, The wires are not supposed to be twisted first, The wires are supposed to be placed side by side and the nut is supposed to do all the work when you twist it on.

IMHO that is incorrect.  You are supposed to use your "electrician's linemans" pliers to twist all wires before twisting on a wire nut.  Actually, the twisted wires are to make the electrical connection, the nut secures it, and provides the insulative covering.  And yes, you should pre-twist any combination of solid or stranded wires before installing a nut.  Ever unscrew a nut and try to pull apart wires that were properly twisted before the nut was installed?  That is the sign of a good connection that you don't have to worry about burning down a house 10 years later and getting sued for.  Always pre twist your wires.

[LEXX]

You're righton there, stranded wire is famous for pulling out of connections and especially for "strays", all stranded needs to be checked very carefully, to me it sounds like the refrigeration guy was very inexperienced at doing the terminating inside the units.  Most people would have noticed those sorts of things.  What can you say, it's hard to get good help these days ;-)

LEXX

[Volvo farmer]

You are supposed to use your "electrician's linemans" pliers to twist all wires before twisting on a wire nut.  Actually, the twisted wires are to make the electrical connection, the nut secures it, and provides the insulative covering.  And yes, you should pre-twist any combination of solid or stranded wires before installing a nut.  Ever unscrew a nut and try to pull apart wires that were properly twisted before the nut was installed?  That is the sign of a good connection that you don't have to worry about burning down a house 10 years later and getting sued for.  Always pre twist your wires.


Hmmm. You are probably right, especially for home wiring. I'll just give this reason as to why I said that. My experience is in appliance repair and there's instructions right on the dryer element box for putting together (2)10 ga stranded wires for a 5000W 240V connection. They say to put the wires side by side and let the nut do the work connecting them. I've been doing it that way for years and it works. Perhaps the most important thing in this application is to keep the copper well shielded inside the nut and that's why they say to do it that way.

[nothing to lose]

This is why I myself don't beleave in codes and book learned professionals that write the codes and tests.

I had a refrigeration guy BURN OUT both my freaon shut off valves AND the furnace blower motor!

First he had problems soldering new copper tubbing onto the shut off valves and burnt those out. Had to tak them off then he some how managed to solder the new tubing to the old tubing, but took him awhile. Now my outdoor colling unit does not have the shut off valves. When disconnecting it like for moving you shut one valve off and pump it up then shut off the other valve. This traps the frean in the unit and empty the lines so it can be taken lose. Not now, but that's ok, it worked awhile but by the next year it was out of freon, wonder why??

As for the motor, he wired up the furnace blower in the house, turned on the breakers, turn on the air conditioner, it worked in low speed for a few seconds, tried to hit the next speed and blew magic smoke 3' out against the other wall (looked like a mushrooom cloud on it's side) and the fire shot about 1' itself. Only a split second it blew, but it filled two rooms of the house with smoke.

 When the OTHER guy brought out the new motor and took ou the fried one he said the first guy had the motor wired direct to ground when it kicked off the low speed to the higher speeds and that's what happened there.

Hmm, and the first guy had a lisence to do this work?? Yep!

Kinda young guy, probably book learned and this was his first field job maybe??

Lucky for me all the costs to connect it and get it working was in the purchase contract when I bought the trailer house

I never did get the electric furnace working right (but I never wanted the use it either) and the airconditionare worked great for the first month, then it was running all the time and the house was still hot the second month or so and the next year  it run but did nothing.

Anytime you know how to do something always check the pros work after he's done!

Heck I even had to nail down a roof after friends ran off a contractor building thier house. He had missed the trusses all over the place when nailing down the roof sheeting. Not just a few nails, but whole rows! About 1-2" away from the trusses a row of nails perfectly straight not doing anything but poking out from plywood into thin air. And this was alot of places, not just one wrong measurement, and he had a lisence too.

Most pros are just that, professional and worth the money probably, but far to many pros are HACKS too, that lisence in most cases just means they paid a fee for nothing.

[elvin1949]

nothing to lose

you know the old saying.

want it done right do it yourself.

later

elvin