FZ 114 High Pressure Switch

[swissjohn]

Hi all. I'm not a refrigeration engineer and I need some help please.
I bought an ex Sainsburys van fridge box to use as a cold room for my farm shop. It came with some Hubbard wiring diagrams which although are pretty basic, helped me wire it up. I got it running off a new large leisure battery and with the help of a large battery charger, it ran for 2 days but was turned off at night. I kept getting a fault code on the controller which flashed HPS but it carried on running perfectly with temperature going down to 2 degrees, stopping and restarting at 4 degrees with the odd defrost in between. Then I shut it down to tidy up the wiring to the controller which I had left at the length it came with. I shortened it to the length I needed so as to mount the controller where I wanted it. When I went to restart it there was a very loud click and nothing. The controller was showing HPS fault. The loud click which happens every time I tried to start is the HPS switch switching on and immediately switching off again.
Does any one have any idea what the problem could be.
Thanks for any help.
John

[cadwaladr]

Is the fan on the outside part of the unit running from memory it has a plug on it so you can disconnect when removing the cover.

[swissjohn]

Yes the fan was running and yes it has a disconnect plug.

[cadwaladr]

That's strange because if it's been off for a while like overnight the head pressure would drop and if it sensed high pressure it would stop and show that alarm you may have a faulty switch but you need to know what pressure is in the system and you are not a fridge engineer with test gauges do not even be tempted to bypass the switch,get a local fridge man out this thing isn't in a hot environment is it giving the condensor a rinse out would do no harm the condensor is the outside bit use a hose and washing up liquid not a pressure washer as that would damage the fins.

[Grizzly]

Hi swissjohn.
I am with cadwaladr, you seem to be locked out on a H.igh P.ressure S.witch Fault.
This may be electrical or Mechanical or both?
I am guessing the click is the compressor or Fan contactor. But the safety circuit is holding off the supply?
Anyway as suggested contacting a local "Fridgie" is the best bet now.
Where are you in the U.K. Someone on the forum should respond.
Grizzly

[swissjohn]

Thanks for your replies Cadwaladr and Grizzly.
What I forgot to mention in my original post is that I had my local man who looks after my shop freezers and chillers out to re gas it (I won't tell you why - it's embarrassing :rolleyes:)
The 12v power cable connects to a largish switch - I'm presuming magnetic, and when I press the on button on the controller the switch is activated and supplies power to the control panel which in turn powers everything that needs power. This is the switch that makes the loud click as it activates and straight away switches off again.
Because of all the HPS fault codes I had that didn't affect the running and then the final one that stopped it from running do you guys think the switch might be faulty or could it be the circuit board in the control panel. If it is the switch it looks as though I would have to have it regassed again.
Your thoughts please.
Thanks. John

[swissjohn]

Oh by the way, I'm in skegness.

[Grizzly]

Hi John.
A bit far for me then!
I am intrigued as to what is happening?
You could have an issue with the supply contactor / largish switch, or it could be a safety / control circuit issue
as already discussed.
Maybe the coil in the contactor is faulty or the contacts are pited and were sticking in before.
Who knows I can think of lots of issues that can be easily eliminated once on site and actually looking at what you have got!
I think you need your fridge guy back to at least assist with the diagnosis.
Sorry but the fault showing has a relevance.

Interesting all the same! Please keep us informed.
Grizzly

[Grizzly]

Back again. This switch would not be item 48 would it?
Grizzly

13738


1
3TST024

Cabin Controls




2
Need Unit SN#

A.C. Motor Plate




3
Need Unit SN#

D.C. Motor Plate




4
2QECFZ1002

Electric Panel




10
Need Unit SN#

Base




11
3CND172

Condenser




12
3CVS017

Solenoid Coil




14
Need Unit SN#

Right Condenser Closing




15
2708024

Left Condenser Closing




16
3CGT052

Belt 7M=615 (CN7MR615)




17
3CGT088

Belt 7M=650 poliflex




18
3002083

Case FZ114




19
3CMP605

Compressor FRASC.C204 O.ESTERE




21
3PMS002

Crunckshaft seal




23
3FLT100

Filter 3/8 FSA




25
3GRI041

Grid




29
Need Unit SN#

Humidity Indicator




32
3MOR038

Terminal Board




33
3MTR090

Electric Motor




34
3MTR022

D. C. Motor MP80L 12V G1400 W600




35
3MTV090

Fan




36
2011090

Separator Bracket




37
3PRS040

Pressure Switch Hp




38
3PLG075

Pulley D.70 7M D.14




39
3PLG074

Pulley D.110 7M OMT




40
3PLG121

Pulley D.70 7M D.24




42
3RBN102

Shut off valve




43
3SRP002

Tank




44
2706006

Filter Support




45
2700505

Valve Support




48
3TLR110

Contactor




49
3VRP004

Regulating Valve




50
3VLS028

Solenoid Valve




52
3SPZ003

Brushes



https://www.completetransportrefrigeration.com/images/3c80853c6caf64b94c62053d4ad3069c.png




3
3EVP266

Evaporator




4
2708042

Cover




5
3DDO071

Nut X ATT.O-R 11/16"-16 UN




6
3DDO072

Nut X ATT.O-R 13/16"-16 UN




7
3BUL058

Thermostatic Valve




9
2GUN006

Union 11/16”-16Un(3/8 Or)C.Fl




10
2GUN007

Union 13/16"-16UN(1/2 OR)C.FL




11
3GRI040

Grid




12
3GUR026

Gasket O-R 8x2




13
3GUR027

Gasket O-R 12X2




14
3INF002

threaded insert M 6




15
3MTV077

Fan




16
3ORF002

Orifice 01 TEF/Y/X 2




17
3RND038

Plain Washer D.6X12




18
3SNS061

Thermostat Probe




19
2708043

Bracket




20
3TPO017

Cap




21
3TPO018

Cap




22
3VTE195

Screw 6x16

[cadwaladr]

Does this thing run on twelve volts dc or 240 ac ? If 12 are the brushes ok in the drive motor.

[swissjohn]

Hi again Grizzly. Yes, that looks like the switch that does the clicking. It is the first thing that has 12v to it all the time. I now know what it's called ;) and thanks very much for taking the time to find and list the exploded diagram.
Cheers. John

[swissjohn]

Hi again Cadwaladr. Yes, it is 12v only and the motor runs fine. I've powered that up directly to test it.

[Grizzly]

Hi again Grizzly. Yes, that looks like the switch that does the clicking. It is the first thing that has 12v to it all the time. I now know what it's called ;) and thanks very much for taking the time to find and list the exploded diagram.
Cheers. John

Hi John.
If I am teaching you to suck eggs then I apologise in advance.
If the 12v is on one side of the witched terminals then that is to be expected. But if the coil contacts have 12v on then permanently then it is indeed the coil at fault.
Your move!
Cheers Grizzly

[cadwaladr]

Apollo thirteen comes to mind on this one ha ha.

[swissjohn]

What I intend to do now is try bypassing the HPS temporarily to see what happens. If it fires up and runs ok then by my thinking it shows that the HPS is at fault and vice versa.
The Contactor has power going in all the time but only activates when I press the Go button on the controller. So there must be power going through to the CPU circuit board for the Controller to function. If the HPS is not at fault then it must be either the Contactor coil OR the CPU Circuit board. But which one?????
Talking to you two on here helps me think things through and writing my thoughts down helps as well.
So thank you both for bothering to help.
I will report back and let you know what happens. It won't be tonight because I have to go to the wholesale fruit market which is in Hull, 70 miles away. No sleep tonight!!
Thanks again guys.
Cheers. John

[swissjohn]

Well, it's been a busy weekend in the shop so could only have a look today. Did what I said I would - bypassed the HPS and guess what - it works. Runs like a dream.
Now, I know that I shouldn't do it, but I really think it is just the switch. I only had it regassed just before the problem occured and as I said earlier, I kept getting HPS error messages with no sign of a problem. I now have to source a new HPS and get my fridge man out to fit it and regass it again. I will do this as quick as I can BUT I need to run it during the day to keep my stuff fresh. What do you two think? Can I risk it? What is the worst that can happen? Apollo 13 cadwaladr - thanks for that!!!!!!
Cheers. John

[cadwaladr]

Give that condensor a wash for sure,desperate times call for desperate measures changing the switch will mean no loss of gas because there should be a Schrader valve but make sure you have a spanner on the stub it fastened to.

[swissjohn]

Thanks for the tips - will do! So it's not going to do an Apollo 13 on me??? Its been running perfectly all day today but switched off for the night.

[cadwaladr]

You could order the part and fit it yourself do as I told you with holding the fitting on the pipework,Hubbard will charge you a pretty penny but may save paying your fridge man another callout.