How do we stop this

[LRAC]

Not posted for a while up to our necks in it (work that is).

We have a blast freezer on site 25hp pw start system evaporating at -35 no problems with the system except the customer insist turning the unit off over the weekend. We have installed a control panel with a shutdown/pumpdown switch but the customer always switches it off from the isolator on the panel door. As you can imagine he has blown 2 compressors in 14 months from liquid damage as the control panel shuts off the cranckcase heater and no pumpdown taking place etc.

Other than bypassing the isolator (which would be illegal) have you any suggestions, we take the blame for them not following the correct procedures on shutdown????????

[Springbok]

Hey welcome back LRAC...once again you're just proved the point that the customer never listens when an engineer speaks,even when it does cost them at the end of the day.

I guess when I would suggest labelling the board in bright red wouldn't help either?

[Toosh]

Not posted for a while up to our necks in it (work that is).

We have a blast freezer on site 25hp pw start system evaporating at -35 no problems with the system except the customer insist turning the unit off over the weekend. We have installed a control panel with a shutdown/pumpdown switch but the customer always switches it off from the isolator on the panel door. As you can imagine he has blown 2 compressors in 14 months from liquid damage as the control panel shuts off the cranckcase heater and no pumpdown taking place etc.

Other than bypassing the isolator (which would be illegal) have you any suggestions, we take the blame for them not following the correct procedures on shutdown????????

Hi LRAC Is it possible to have a remote pumpdown switch beside the isolator switch only a thought

Regards Norm

[The Viking]

Actually,

I just been to a new site where I couldn't turn the door isolator off at all.

Turned out that someone fitted a lock to it, it looked as if it were a "proper" accessory.
A half moon structure were fitted to the shaft of the isolator and the bolt from a lock stopped it from rotating.
I haven't described it very well have I??

I have to go back to site next week, I get some photos..

(On the site I went to they had mislaid the key and in the end I had to drill the lock..)

[Electrocoolman]

Hi LRAC,
How about a battery backed alarm siren and strobe linked to supply from isolator, that will not reset once power has been switched off. This would scare him sh*tless.

Could also make it inhibit startup of machine so that it requires your intervention to get it up and running, but depends on your service contract .... callout could be cheaper than another compressor!

They might not like loosing production time the following Monday.


Perhaps ABE could advise a legal route to send them a legal letter...need to look at T & C's of service contract.

[monkey spanners]

You could fit a seven day time clock in the control panel to turn the sytem off properly automaticaly and to save the customer the 'trouble' of turning it on and off himself.

Jon

[taz24]

Not posted for a while up to our necks in it (work that is).


Other than bypassing the isolator (which would be illegal) have you any suggestions, we take the blame for them not following the correct procedures on shutdown????????

Hi LRAC

I'm sort of tempted to say

"let him turn it off"

If he is paying the bills and is quite prepared to stump up the cost of new compressors then, thats his call and so be it.

taz.

[Reefer Madness]

Good day one and all.

If you have told the customer and backed it up with a written explanation of their actions and they continue, let them keep paying for new compressers and your time etc.

[Andy W]

What I would do is fit a relay accross the isolator (would have to be fused from the live side) with a flashing strobe and buzzer so when the isolater is turned off a relay can make or break and sound a deafining buzzer and flashing strobe and will only extuingish once the isolater is switched back on, this may encourage them to use the pump down switch.

Depending on how complex you want to go, once isolater reinstated you could have an anti cyle timer which warms up the CCH for so many hours or minutes prior to the control circuit been made good again and even have a push button reset for the control circuit as well, the possibilities are endless, all depends on costs and who is going to pay for it.

[Grizzly]

Nice one.

Am I correct in thinking the customer is shutting the system down but not admitting to it.
Thereby leaving yourselves to foot the bill as the contract is all inclusive?

A simple solution would be to get the suspect or anyone in authority on site to witness.
Preferably signed, the fitting of a container seal the type used by transport companies.

In an Emergency these can be broken but more importantly any unauthorised access in highlighted.

Something along those lines may help Hopefully.
Grizzly

[LRAC]

Just a thought what do you reckon to having a seperate starter panel just for the compressor plant working on hp/lp pumpdown and just having the control circuit panel on the inside where the customer has access.

This might fool them in thinking they have isolated the whole system but they have only killed the control circuit to the solenoid valve,defrost,fans etc.

The compressor plant would then be able to perform a correct stop & start procedure.

Any thoughts on that???????????

[Kh1971]

Hi,

Such people you cant change at all, so it is always better to write in the contract and let hem pay it

Regards

Khalid

[frank]

You could always fit a 'Delay On Timer' into the main isolator circuit so that it delays for 6 hours when the isolator is put back on - to give the crankcase heater time to evaporate all of the sump liquid refrigerrant.

I don't suppose he would be very happy at waiting 6 hours on a Monday morning though for his kit to be available but at least he might just sit up and take notice

[richardb14]

Just a thought what do you reckon to having a seperate starter panel just for the compressor plant working on hp/lp pumpdown and just having the control circuit panel on the inside where the customer has access.

This might fool them in thinking they have isolated the whole system but they have only killed the control circuit to the solenoid valve,defrost,fans etc.

The compressor plant would then be able to perform a correct stop & start procedure.

Any thoughts on that???????????

thats what I would do - and it still complies with the regs

[Andy W]

thats what I would do - and it still complies with the regs

The panel has to be clearly labelled that mains isolation is now elsewhere, I am pretty sure that is a requirement. How about putting a padlock or security tie on the isolator and fitting a push button e stop for the lazy buggers instead.

[nike123]

You could always fit a 'Delay On Timer' into the main isolator circuit so that it delays for 6 hours when the isolator is put back on - to give the crankcase heater time to evaporate all of the sump liquid refrigerrant.

I don't suppose he would be very happy at waiting 6 hours on a Monday morning though for his kit to be available but at least he might just sit up and take notice

I done that on number of installations after I changed 8 compressors at one hotel (3 air to water heat pumps with 2 compressors each). Stupid maintenance guy will simply turned of and on all main switches even I put stickers with warning that it must be turned on for 24 hours before he could turn on the control switch. I told to owner that his employer is responsible for that compressor breaking, but he did not believe me, because they are relatives. After I fitted delay-on relays (24 hours delay) there is no compressor braking any more. After two years of no compressor braking (and 8 compressors later), owner has kick his relative.