The purpose of the EPR valve is to maintain a constant pressure in the outlet side to the evaporator,?
particularly during compressor ____________________.
Fill in the blank for me anyone who could help would be greatly appreciate it.
- Mr. KnowItAllLv 71 decade agoFavorite Answer
The Exhaust Pressure Regulator (EPR) valve and solenoid operate in conjunction with the EGR valve. The EPR valve's job is to increase exhaust backpressure in order to increase EGR flow. The EPR valve is usually open, and the solenoid is normally closed. When energized by the B+ wire from the Throttle Position Switch (TPS), the solenoid opens, allowing vacuum to the EPR valve, closing it. This occurs at idle. As the throttle is opened, at a calibrated throttle angle, the TPS de-energizes the EPR solenoid, cutting off vacuum to the EPR valve, closing the valve. Two other solenoids are used for EGR valve control. The EGR solenoid allows vacuum to reach the EGR vent solenoid under certain conditions. The vent solenoid then controls the EGR valve to regulate the flow of gasses into the intake manifold.
The EPR valve is used mostly on water coolers, on units where high humidity is required (such as fruit and vegetable stowage spaces), and in installations where two or more rooms are maintained at different temperatures by the use of the same refrigeration unit.
A cross section of a common EPR valve is shown in figure 16-15. The tension of the spring above the diaphragm is adjusted so that when the evaporator coil pressure drops below the desired minimum, the spring will shut the valve.
The EPR valve is not really a temperature control-that is, it does not regulate the temperature in the space. It is only a device that prevents the temperature from becoming too low.