It is due to pressure rising due to a bad condenser fan motor, bad capacitor, obstructing of airflowat the condenser, or a dirty condnser.
water as a coolant
fan cycling.3 way modulating valve
non condensebles in system dirty cond coil high ambient poss over charge
Head = (Pressure * specific gravity)/2.31 Head in ft Pressure in pound per in^2
static head
Excessive head pressure.
5 Causes of high head pressure: 1.) Dirty condenser tubes 2.) High temp entering condenser water 3.) Low flow of condenser water 4.) Water bypassing at division plate 5.) Non-condensables in the system
water as a coolant
Poor compressor performance should result in low head pressure as the system cools better than the compressor can pump.
The head pressure and compressor current would normally rise (strong winds and/or rain and/or very low air temperatures will reduce this effect). Less heat would be removed from the refrigerant and therefore deliver less cooling.
1.Air Flow 2.Over charged unit 3.Dirty evaporator and condenser coils.4.High amp draw
They do fail naturally but the some causes are engine overheating because of water pump failure, pressure problems in the head and water cooled oil coolers splitting and blocking the circulation leading us back to point 1.
Very high
check condenser
high head pressure and a higher supply temp.
High head pressure is due to the lack of heat removal during the condensing process of the refrigerant cycle. The outdoor condenser is there to transfer the heat out and condense the refirgerant into a liquid. When ever the condenser is dirty or the fan motor is not working right the result is an increase in temp. and since pressure and temp are directly related the refirgerant pressure is increased thus the term high head
fan cycling.3 way modulating valve