Misleading error merrage

[Guner Edip Riza]

Carrier Transicold Maxima 2
Error message: hi press


While helping out to a friend fixing a trailer, I was misled by the error message displayed on the control box.
I have guided my friend to check all the pressure switches and wiring on the discharge side of the system with no luck.
I felt a bit silly when the problem came out to be refrigerant shortage.
As soon as the system was charged with refrigerant all started running perfectly.
I could not obtain a service manual for this trailer or a circuit diagram, therefore I could not find out why the system was displaying hi press message while it was completely short of refrigerant.
Any comments?

Guner

[cadwaladr]

It should have brought up a alarm code,and on the inside of the unit door is a sticker relating to what the codes refer to .

[Grizzly]

Carrier Transicold Maxima 2
Error message: hi press


While helping out to a friend fixing a trailer, I was misled by the error message displayed on the control box.
I have guided my friend to check all the pressure switches and wiring on the discharge side of the system with no luck.
I felt a bit silly when the problem came out to be refrigerant shortage.
As soon as the system was charged with refrigerant all started running perfectly.
I could not obtain a service manual for this trailer or a circuit diagram, therefore I could not find out why the system was displaying hi press message while it was completely short of refrigerant.
Any comments?

Guner


Just maybe the condenser fan failed or some other issue caused an High pressure situation and your PRV lifted?
If fitted?
Which would result in a High pressure fault being displayed (Manual reset required?) but the system being short of refrigerant!
Just a guess mind!
Grizzly

[IRMechanik]

High pressure is a catch all code. Several things can trigger it. Depending on which software revision you have it could be running in a vacuum for more than five minutes it will trigger a high pressure code. Or if the discharge air is reading higher than return air it will also trigger this code. Even turning the switch on and off too fast will give you high pressure.

[sonkax]

The wire than comes from pc board goes thrugh hp then lp swich, that's why they have the same connector, no matter how you connect them the result is the same hi press alarm for hi pressure or vacum on low side.