In the last few days of our just completed trip I found the dometic T rated fridge was not cutting it when running on either 12v or 240v. On gas it seemed to work fine.
When running on power it struggled to stay below 9degC in the cabinet. This has never been a problem with this fridge before as last year we travelled through the north with outside temps of 35 - 40 degC not uncommon.
Is there a component common to 12v and 240v in the fridge? I would think the elements would be separate units but I could be wrong.
I have fitted a baffle on top of the fridge (external) and also a thermostatically operated fan to vent hot air from around the fridge which, as I said, worked perfectly last year.
The van / fridge is less than 3 years old.
I guess I am asking if there is a easy fix for this which I can do, or does the van need to go to the doctor?
Cheers
DeBe said
02:20 PM Nov 22, 2009
Hi Delta18 The 12v & 240v elements are seperate the thermostat will probably be a common unit with 2 sets of terminals one for 12V & one for 240V. If its working ok on gas then it basicly should be ok. If its not cutting it on electric ( asuming you have turned up the thermostat) then it posibly a faulty thermostat, goin on your description. cheers Daryl
Delta18 said
03:07 PM Nov 22, 2009
Thanks Daryl, in the past I have never needed to touch the thermostat when switching between the three power supplies. When on 3 1/2 to 4 it was about .5 degC in the morning, then by evening with opening & closing during the day, it would creep up to 4 1/2 to 5 degC which I was happy with.
I know the thermostat has no effect when on 12v as it is always going full bore and is not adjustable.
I think I am going to have to get a Techie to look at it .
Cheers
-- Edited by Delta18 on Sunday 22nd of November 2009 02:13:51 PM
oldtrack123 said
05:12 PM Nov 22, 2009
Delta18 wrote: I know the thermostat has no effect when on 12v as it is always going full bore and is not adjustable. I think I am going to have to get a Techie to look at it .
Cheers
-- Edited by Delta18 on Sunday 22nd of November 2009 02:13:51 PM
Hi Delta The thermostat does control the gas as well
, should cut back to a smaller flame when @ set temp. Perhaps you have a clogged jet or low gas pressure & flame is much smaller than it should be. The thermostat switching & sensing is common on both 240v &12v so still could be a thermostat problem. Check thermo tip is still firmly clamped to evaporator [ inside fridge section ]
justcruisin01 said
05:40 PM Nov 22, 2009
We have found some places the 240v is only around the 220-230v. this has big efects on our car fridge , the 240 transformer needs min 230v. 12v, check your power supply & fuses.,As you turn the thermo switches to off & back on you should be able to hear a click of the contacts in the thermo switch .
jimricho said
06:20 PM Nov 22, 2009
As mentioned the 12volt element wiring bypasses the thermostat and therefore is "on" full time. Also the 240 volt and 12 volt systems are entirely independent of each other so the two issues may well be separate problems.
I have found the 12 volt element needs about 14 volts to operate efficiently and I have installed a voltage booster to overcome this problem. (I was able to test this out over a two day period using a 14.5 volt 25 amp power supply)
Also the fridge needs to be level to operate properly and this is near impossible when travelling.
It would be worth checking the (240v) voltage as suggested in one of the posts above but my feeling is that there could be a problem with 240v element as you mention it has operated satisfactorily on previous occasions and the fridge still does when operating on gas. I think this may be a job for a techie to check out as you have suggested.
PS: I make no claim to being "3 way fridge expert"
-- Edited by jimricho on Sunday 22nd of November 2009 05:23:54 PM
oldtrack123 said
09:12 PM Nov 22, 2009
Hi Jim
"As mentioned the 12volt element wiring bypasses the thermostat and therefore is "on" full time. Also the 240 volt and 12 volt systems are entirely independent of each other so the two issues may well be separate problems"
That statement is not 100% correct some dometic model do have thermo control on 12v & use the same thermo as for 240v[ just switch the input & output]
If the fridge is receiving 12v @ it's terminals under load it should operate quite satisfactory, majority of correctly installed ones do This fridge has been ok in the past off straight 12v so why change now?
When travelling the motion is quite adequate to avoid gas locks unless on a slope for hours
Jim ,if you have to supply 14v to your fridge perhaps the entire installation needs checking to see if it meets manufacturer's installation instructions. Putting 14v to a 12v element encreases its wattage rating by about 36%, it may have a SHORT life If your fridge is a large model the 12v element may be a lower wattage than the240v element & may be pushing in hot weather, it may be possible & if so more suitable to get a higher rated element .BUT correct cabling & baffling will be extra important then.
jandas fun said
09:32 PM Nov 22, 2009
Delta18 wrote:
Hi Guys,
I have fitted a baffle on top of the fridge (external) and also a thermostatically operated fan to vent hot air from around the fridge which, as I said, worked perfectly last year.
hi Delta 18, where did you wire the fan into? don't know much about this, but have been reading my fridge manual, following on from the other post. In part it says"do not connect any other electrical equipment to the refrigerator circuit................a resulting voltage drop will cause a decreased cooling capacity. Hope this helps. if not at least i'm learning something.
Johnw
oldtrack123 said
11:28 PM Nov 22, 2009
jandas fun wrote:
hi Delta 18, where did you wire the fan into? don't know much about this, but have been reading my fridge manual, following on from the other post. In part it says"do not connect any other electrical equipment to the refrigerator circuit................a resulting voltage drop will cause a decreased cooling capacity. Hope this helps. if not at least i'm learning something.
Johnw
Hi John The fans have a very low current draw will not give a voltage drop problem & can be wired in @any convienient point @ rear of fridge ,MAKE SURE IT IS THE 12V CIRCUIT WE DON'T WANT YOU OR THE FANS GOING WHOOF
The manual is quite correct in meaning "run a direct line to fridge only" & they rightly point out the problem of voltage drop, too bad van makers don't read the instuctions
jimricho said
06:34 AM Nov 23, 2009
oldtrack123 wrote:
Hi Jim
"As mentioned the 12volt element wiring bypasses the thermostat and therefore is "on" full time. Also the 240 volt and 12 volt systems are entirely independent of each other so the two issues may well be separate problems"
That statement is not 100% correct some dometic model do have thermo control on 12v & use the same thermo as for 240v[ just switch the input & output]
If the fridge is receiving 12v @ it's terminals under load it should operate quite satisfactory, majority of correctly installed ones do This fridge has been ok in the past off straight 12v so why change now?
When travelling the motion is quite adequate to avoid gas locks unless on a slope for hours
Jim ,if you have to supply 14v to your fridge perhaps the entire installation needs checking to see if it meets manufacturer's installation instructions. Putting 14v to a 12v element encreases its wattage rating by about 36%, it may have a SHORT life If your fridge is a large model the 12v element may be a lower wattage than the240v element & may be pushing in hot weather, it may be possible & if so more suitable to get a higher rated element .BUT correct cabling & baffling will be extra important then.
Hi "oldtrack123",
Re the 12volt wiring bypassing the thermostat, this is so on my Dometic and I assumed this would be "normal" however I accept that other brands and perhaps other models in the Dometic range may have the thermostat connected to the 12 volt circuit.
Regarding operation on 14 volts, this voltage is the normal operating voltage of a vehicle's electrical system when the engine is running (13.8 - 14.5 volts) as the alternator is then the primary source of electrical power. All "12volt" devices designed to be used in a vehicle are (or should be) designed to operate at this voltage. This would, I feel sure, apply to any fridge designed to be used in a vehicle or caravan. If the fridge were installed in motorhome and the cable run from the battery/alternator were short and of adequate gauge (as it should be) I would imagine the voltage drop would be much less the two volts or more (sometimes significantly more) that occurs in a typical caravan installation.
Maybe you've come across an actual situation where a faulty element was proved to be a result of running it on 14 volts. If so let me know and I'll reset the voltage on my booster.
Regards,
Jim
PS: I originally purchased the booster for a different application but have not gone ahead with this as yet, so I decided to try it out. Without the booster the voltage at the fridge terminals is 11 volts so the booster gives me a 62% increase in wattage.
My little Goldstream wind-up van came originally with a 12pin connector and the fridge wired independently to the van's other 12volt stuff. I have replaced the 12pin with a large 7 pin connector for compatibility with two other trailers I own and wired the vehicles fridge circuit with 6 mil cable. The earth return is properly bonded to the vehicle chassis near the connector. The cost to re-cable the system using (say) 8 gauge cable and Anderson connectors is well in excess of the $90 I paid for the booster.
-- Edited by jimricho on Monday 23rd of November 2009 05:38:04 AM
-- Edited by jimricho on Monday 23rd of November 2009 06:00:31 AM
edit 3....damn keyboard!...not my fault
-- Edited by jimricho on Monday 23rd of November 2009 06:03:20 AM
oldtrack123 said
12:23 PM Nov 23, 2009
HI Jim
Yes I agree equipment designed for auto use should be able to tolerate to 14.5 v short term..Once batts reach this state of charge they normally cut back to 13.4<13.8. At 13 .8v,unless Very heavy cables are used throught it is likely that ,at least .75v will be lost under load, volts @ fridge down to 13v which I believe is a very good compromise between performace & element life.
I believe any fridge that does not perform on13v has some other problems.
Your comments re motor homes are valid if the wiring is adequate[ but again as above re voltage] yet on this & other forums many H/mers are finding voltage as low as 11v. A voltage which is next to useless as you have found out. With your set up I assume are getting the full14v @ the fridge Elements do have more tolerance to higher voltage than other equipment & the differance in life span possibly does not mean much in the overall life of the van , depending on frequencyof use etc
You seem to have done the right things for performance with the Goldstream
In the last few days of our just completed trip I found the dometic T rated fridge was not cutting it when running on either 12v or 240v. On gas it seemed to work fine.
When running on power it struggled to stay below 9degC in the cabinet. This has never been a problem with this fridge before as last year we travelled through the north with outside temps of 35 - 40 degC not uncommon.
Is there a component common to 12v and 240v in the fridge? I would think the elements would be separate units but I could be wrong.
I have fitted a baffle on top of the fridge (external) and also a thermostatically operated fan to vent hot air from around the fridge which, as I said, worked perfectly last year.
The van / fridge is less than 3 years old.
I guess I am asking if there is a easy fix for this which I can do, or does the van need to go to the doctor?
Cheers
I know the thermostat has no effect when on 12v as it is always going full bore and is not adjustable.
I think I am going to have to get a Techie to look at it .
Cheers
-- Edited by Delta18 on Sunday 22nd of November 2009 02:13:51 PM
The thermostat does control the gas as well
, should cut back to a smaller flame when @ set temp.
Perhaps you have a clogged jet or low gas pressure & flame is much smaller than it should be.
The thermostat switching & sensing is common on both 240v &12v so still could be a thermostat problem.
Check thermo tip is still firmly clamped to evaporator [ inside fridge section ]
this has big efects on our car fridge , the 240 transformer needs min 230v.
12v, check your power supply & fuses.,As you turn the thermo switches to off & back on you should be able to hear a click of the contacts in the thermo switch .
I have found the 12 volt element needs about 14 volts to operate efficiently and I have installed a voltage booster to overcome this problem. (I was able to test this out over a two day period using a 14.5 volt 25 amp power supply)
Also the fridge needs to be level to operate properly and this is near impossible when travelling.
It would be worth checking the (240v) voltage as suggested in one of the posts above but my feeling is that there could be a problem with 240v element as you mention it has operated satisfactorily on previous occasions and the fridge still does when operating on gas. I think this may be a job for a techie to check out as you have suggested.
PS: I make no claim to being "3 way fridge expert"
-- Edited by jimricho on Sunday 22nd of November 2009 05:23:54 PM
where did you wire the fan into?
don't know much about this, but have been reading my fridge manual, following on from the other post.
In part it says"do not connect any other electrical equipment to the refrigerator circuit................a resulting voltage drop will cause a decreased cooling capacity.
Hope this helps. if not at least i'm learning something.
Johnw
The fans have a very low current draw will not give a voltage drop problem & can be wired in @any convienient point @ rear of fridge ,MAKE SURE IT IS THE 12V CIRCUIT WE DON'T WANT YOU OR THE FANS GOING WHOOF
The manual is quite correct in meaning "run a direct line to fridge only" & they rightly point out the problem of voltage drop, too bad van makers don't read the instuctions
Re the 12volt wiring bypassing the thermostat, this is so on my Dometic and I assumed this would be "normal" however I accept that other brands and perhaps other models in the Dometic range may have the thermostat connected to the 12 volt circuit.
Regarding operation on 14 volts, this voltage is the normal operating voltage of a vehicle's electrical system when the engine is running (13.8 - 14.5 volts) as the alternator is then the primary source of electrical power. All "12volt" devices designed to be used in a vehicle are (or should be) designed to operate at this voltage. This would, I feel sure, apply to any fridge designed to be used in a vehicle or caravan. If the fridge were installed in motorhome and the cable run from the battery/alternator were short and of adequate gauge (as it should be) I would imagine the voltage drop would be much less the two volts or more (sometimes significantly more) that occurs in a typical caravan installation.
Maybe you've come across an actual situation where a faulty element was proved to be a result of running it on 14 volts. If so let me know and I'll reset the voltage on my booster.
Regards,
Jim
PS: I originally purchased the booster for a different application but have not gone ahead with this as yet, so I decided to try it out. Without the booster the voltage at the fridge terminals is 11 volts so the booster gives me a 62% increase in wattage.My little Goldstream wind-up van came originally with a 12pin connector and the fridge wired independently to the van's other 12volt stuff. I have replaced the 12pin with a large 7 pin connector for compatibility with two other trailers I own and wired the vehicles fridge circuit with 6 mil cable. The earth return is properly bonded to the vehicle chassis near the connector. The cost to re-cable the system using (say) 8 gauge cable and Anderson connectors is well in excess of the $90 I paid for the booster.
-- Edited by jimricho on Monday 23rd of November 2009 05:38:04 AM
-- Edited by jimricho on Monday 23rd of November 2009 06:00:31 AM
edit 3....damn keyboard!...not my fault
-- Edited by jimricho on Monday 23rd of November 2009 06:03:20 AM
Yes I agree equipment designed for auto use should be able to tolerate to 14.5 v short term..Once batts reach this state of charge they normally cut back to 13.4<13.8.
At 13 .8v,unless Very heavy cables are used throught it is likely that ,at least .75v will be lost under load, volts @ fridge down to 13v which I believe is a very good compromise between performace & element life.
I believe any fridge that does not perform on13v has some other problems.
Your comments re motor homes are valid if the wiring is adequate[ but again as above re voltage] yet on this & other forums many H/mers are finding voltage as low as 11v. A voltage which is next to useless as you have found out.
With your set up I assume are getting the full14v @ the fridge
Elements do have more tolerance to higher voltage than other equipment & the differance in life span possibly does not mean much in the overall life of the van , depending on frequencyof use etc
You seem to have done the right things for performance with the Goldstream