WD Catalog 2018

7-5

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You can feel for oil at the bottom of all connections (see Figure 7-4) if the

system is not too hot. Of course, a few minutes with an electronic leak

detector is the best way to check for leaks. Keep in mind that pressure is

different in a system at rest, so small leaks may be hard to find. Pressure

in a system at rest, will equalize at from 60 to 95 PSI, depending on

outside air temperature. This means there is more pressure in the low

side of the system at rest than during normal system operation. Just the

opposite is true of the high side; at rest, high side pressure is lower. You

may want to use the detector to check for leaks in the high side when the

air conditioner is operating, if you suspect a leak and can’t find it when

the system is at rest.

Electrical System Inspection

The two stages of an electrical inspection are explained in more detail below:

Inspect Electrical Connections

Check Electrical Current Flow and Device Functions

Use the following procedures to perform an electrical system inspection:

1. Inspect Electrical Connections

First, while you are making your visual inspection under the hood (cab)

and/or at the roof top condenser, take a moment and check all electrical

connections visually and by feel. Look for any corrosion on leads or

connectors and clean them. Make sure all leads and wires are properly

supported and securely connected.

2. Check Electrical Current Flow and Device Functions

Perform the following steps to check current flow and electrical device

functions:

A. Turn the Ignition On

– To check current flow the ignition must

be on.

Electrical System Inspection

Figure 7-4

This illustration shows a

potential refrigerant leak

point at the condenser

fitting.