Manifold Gauge Set

Manifold Gauge Set

Pressure/Temperature Graph, High Side/Ambient Temperature Fig. 1:

System Pressure Fault Classification:

The manifold gauge set is a most important tool for tracing faults and system efficiency assessment. The relationship to each other of HIGH and LOW pressures and their correlation to AMBIENT and EVAPORATOR temperatures must be compared to determine system status (see Pressure/Temperature graphs above).

Because of the heavy reliance upon this piece of equipment for service diagnosis, ensure that the gauges are calibrated regularly and the equipment is treated with care.






1 Low side service hose - BLUE
2 Low side hand valve - BLUE
3 Low pressure compound gauge - BLUE
4 High pressure gauge - RED
5 High side hand valve - RED
6 High side service hose - RED
7 System service hose - NEUTRAL
COLOR (commonly yellow)


Manifold
The manifold is designed to control refrigerant flow. When connected into the system, pressure is registered on both gauges at all times. During system tests both the high and low side hand valves should be closed (rotate clockwise to seat the valves). The hand valves isolate the low and the high sides from the center (service) hose.

Low Side Pressure Gauge.
This compound gauge, is designed to register positive and negative pressure and may be typically calibrated - Full Scale Deflection, 0 to 10 bar (0 to 150 lbf/sq. in.) pressure in a clockwise direction; 0 to 1000 mbar (0 to 30 in Hg) FSD negative pressure in a counter clockwise direction.

High Side Pressure Gauge.
This pressure gauge may be typically calibrated from 0 to 30 bar (0 to 500 lbf/sq. in.) FSD in a clockwise direction. Depending on the manufacturer, this gauge may also be of the compound type.