Thermostats for cabinet coolers

[Temprite]

G'day all.

Just wondering what peoples opinions were on thermostats for small cabinet coolers.

I normally use a ranco VB7.Which measures air temp.

Some cabinets have t/stats inserted into the coil. I assume these have a constant cut in and are similar to a VT9. This way the coil will completely defrost on an off cycle.

Which is the better way?

Thanks in advance.

[chemi-cool]

Dixell,
For every purpose.

Chemi



www.dixell.com

[chillin out]

Dixell,
For every purpose.

This would cost more than the chiller.

Stick to VB7 thats what we use.

If stat is fixed to the coil then its best to get one ordered as they are all differant.

(VL9 will not work on a bottle cooler, the warmest cut out is still too cold.)


Chillin

[Iced-up]

The VB7 stat can be used for both, when placed in the coil it works better, giving a greater off - cycle.

I fit this stat all the time and have yet to go back to an iced-up coil.

[Abe]

VB 7 , best thing since sliced bread

Dont go looking for another.............or trouble

[fridg]

Dixell,
For every purpose.

Chemi



www.dixell.com

CAREL but they do have a probe in the evap
is this the same topic or different

[Abe]

Carel or Dixell is an Electronic controller
Ranco is a very different type of fish

[saud khan]

go for elliwel they r the best most reliable
if using a vb7 you can get a better result if you coil it the it get abetter result working as an ambient state

[martinpsullivan]

Use an Eliwell controller found those the best over the years found Dixell not very good.

[Dan]

Some cabinets have t/stats inserted into the coil. I assume these have a constant cut in and are similar to a VT9. This way the coil will completely defrost on an off cycle.

If you do not have a defrost timer, you should use a thermostat that contacts the evaporator.

[tonto]

I usually use a saginomiya tstat temprite atb-y118 and have never had a drama measures air temp instead of going into the coil... Coldest setting 1 degree warmest setting 9 degrees....

[Temprite]

Well.....

Got a few differing opinions there.

Chillin is right electronic control is to expensive to fit to a bottle cabinet. Although I have used Carel powerstat which has no display but also has it's own defrost timer for off cycle defrost, and is less expensive than a standard t/stat and seperate timer. Carel controllers are used quite a bit here.

I know you can get t/stats from cabinet manufacturers that are inserted in the coil but I was thinking maybe one of the standard service packs from ranco or danfoss would suit.

Iced up.
If you inserted a VB7 into the coil wouldnt it cut out to early as it's coldest cut out is -3 degrees c?.
The danfoss bottle cabinet t/stat may be more suitable for coil it's coldest cut out is -8.5 degrees c

Danfoss 7787008
cold:
cut out -8.5
cut in -1
warm:
cut out 6
cut in 11.5

Ranco VB7
cold:
cut out -3
cut in 2
warm:
cut out n/a
cut in 12.5

Only seems to be on the cabinets in warm kitchens that are overworked and the door is always left open. You change a faulty t/stat with a VB7 only to return to find the coil iced for no reason and then you have to install a timer as well. By that stage you might as well have installed the more expensive electronic control.

Dan you mention a contact t/stat which one do you use?

Thanks for all the replies

[Ybb]

I use either a VB7 or a No. 8 Danfoss inserted into the coil. Both wll give ~3 degrees C if set mid range. Sometimes if the system is out of whack you need to put less into the coil to get it to cut out low enough but that's rare.

[Dan]

We use the Ranco replacement A30 series. Cut in at 40 deg F with a 15 degree differential or an adjustable differential.

[Ybb]

Well.....

Only seems to be on the cabinets in warm kitchens that are overworked and the door is always left open. You change a faulty t/stat with a VB7 only to return to find the coil iced for no reason and then you have to install a timer as well. By that stage you might as well have installed the more expensive electronic control.

If you put a VB7 in the coil you'll never have icing up problems. It's the cheapest control for small cabinets. Sadly it's too good, so tightarse cabinet manufacturers are using them and nothing else so there's sfa in the way of safetys fitted.

[Iced-up]

Temprite,
I do set the vb7 stat close to max or max but it does work well, if you fit the no.8 and set it to max you run the risk of
icing the coil up because of the lower cut out point, the bottles are more than likely being put in at ambient temperature and can cause more problems on pull down.
Again if the cabinet is in a kitchen a defrost timer is a good option, location and demand on the unit are factors, you no yourself these type of calls may need a couple of visits before they are sorted.

[Temprite]

Thanks Ybb and iced-up.

Next VB7 I change I will try it in the coil.
Talked to another mechanic today who also puts them in the coil.

[Andrewcody]

I have just bought a VB7 for a cold room which I use similar to a bottle cooler.

This is the third type of thermostat I have used. The 2 previous had differential temp settings which would just not stabilise as a useable temperature, either driving the compressor too cold (-12C) or too high (+18C), and occaisionally setting at 0 degrees.

My question is this, do I need to sleeve the portion of the capillary tube which is external to the cold room? If I do need to do this can I just use standard pvc spaghetti? or is there something else more suitable?

Or should I mount the whole Thermistor inside the cold room?

Regards
Andrew

[Andrewcody]

If we are talking bottle coolers surely you wouldn't want to be sitting below 0 degrees C ? Just to avoid freezing the contents.

I aim for around +2 to +4 degreesC

[Andy W]

I always use VB7 sensing air. I wrap the end of the capillary around a piece of 3/8" pipe tp make a pig tail and fit it behind the evap fan, I have never had a problem with doing this way and did another one last week on an osborne bottle cooler, I have also used the same thing on Gram refrigerators (sometimes have to tweak the diff though)

Another way is to use those cheap universal +20 / -20 stats with the air sensing bulb on, cost about £8.

Stats can be a real minefield at times and are long over due to be redevolped, what we need is a Ranco type universal stat with an adjustable diff, that would solve a lot of problems and suit a lot of applications. Osborne use an electronic stat (made by Ranco) which has the same size body and fitting as a domestic stat but is electronic with a probe attached, something like that with an adjustable diff would be fantatstic.

[Temprite]

I have been using VXO stats for bottle coolers since starting this thread.

Constant cut in of 4 degrees c and adjustable diff, goes into coil. You will never have icing problems with these.

[Paul@paulrobert]

Im use vb7 all the time they have a nice big differential so no chance of ice ups

[fridg]

I have been using VXO stats for bottle coolers since starting this thread.

Constant cut in of 4 degrees c and adjustable diff, goes into coil. You will never have icing problems with these.

I use these , never an ice up problem , has adjustment screws for cut in and cut out.

Inserted directly in the coil


Danfoss Thermostats

[hd88]

For years i have used 010-1416 ranco temp control. looks like a pressure control but is not. It has a 72" capillary and if you weave that thing through the medium temp evaporator coil, set the cut in at 33 degrees and set the differential at 12 to 15 degrees. that cooler will operate great and you will never get a freeze up. You are just sensing coil temp. this is great for cookline reefers and equipment that is worked out of. If the doors are open all night still no freeze up. once the door is closed it will pull down to temp. You will be a hero to that manager that always has that freezeup problem. What it does is runs that cooler balls to the wall, shuts down and lets the coil warm up to above freezing (cut in 33-34). It will keep the cooler air temp 34 to 38 and your customer will love you. Coolers only, not for freezers. Not for salad coolers for it will freeze lettuce.