Thermo King SB III setting a param's

[jas72]

Ok can someone help me out with the temp ranges on this unit. Like on a Carrier you have ranges A, B, C for when it will start and cool, etc. Also does this unit have a setting for on/off timer?? Ya know controlling how long it will stay off while in range, etc. Thanks for your help.

[chillerman2006]

Hi jas

It's been a while since i have seen an SBIII but as i recall the three positions are

Run = up = constant run controling temp via heat/cool - 3 way valve

Off = middle = Off

Auto = down = automatic stop/start where unit will pull just below set point and then turn off, then start when temp rises, control band is 3 degrees, 1.5 below set point = stop, 1.5 above set point start

Up and Down positions may be the other way round

To check just run to temp and if unit does not switch off you should find the pilot solenoid energise's on the smallest tube from the 3 way valve and the valve should move over to supply heat to the evaporator.

Hope this helps Chillerman :)

[jas72]

Ok that completely lost me lol. More of what I am looking for on the TK unit is to set it like or close to the Carrier I had. On the Carrier it had Temp Range C which was +10/-10 from set point. My settings on it where.

On Timer 4 minutes
Off Timer 90 min (which was max setting)
Temp Range C

so saying my set point was 0 it would not start till it reached +10. And when it fired up it only ran for a few minutes and shut back off.

This SB III fires up every few minutes. Its set at +28 and when it gets to 31-32 it starts. There is no need for that with what I haul. Is there a way of getting it set so it does not start till say 36-38 and if in range stays off, for days if possible lol. Save fuel :)

Thanks for your reply though.

[chillerman2006]

Jas

sorry misunderstood what you were looking for

If it can be done Reeferjon, will know if and how

I will send him a PM to look at this post for you when he is next on line

chillerman

[DaButcher]

Ok that completely lost me lol. More of what I am looking for on the TK unit is to set it like or close to the Carrier I had. On the Carrier it had Temp Range C which was +10/-10 from set point. My settings on it where.

On Timer 4 minutes
Off Timer 90 min (which was max setting)
Temp Range C

so saying my set point was 0 it would not start till it reached +10. And when it fired up it only ran for a few minutes and shut back off.

This SB III fires up every few minutes. Its set at +28 and when it gets to 31-32 it starts. There is no need for that with what I haul. Is there a way of getting it set so it does not start till say 36-38 and if in range stays off, for days if possible lol. Save fuel


Carrier T RANGE "A B C" determines the out-of-range fault alarm temperature tolerance

Setting to TIME STRT instead of TEMP STRT with the on and off numbers at max the way you described is what kept run time to a minimum.

SB III SR does not have a "TIME STRT"
If your SB III is starting every few minutes, extreme ambient temperature or more likely a breakdown in trailer insulation is the cause.

[TX Valve]

This depends on th controller model and Software, On C/S operation the standard default is ..start up 5.1 degrees away from setpoint.

It's important to know the model of the T-stat to give better advice