Every collector with a sensor must have its frame grounded. This ground helps
prevent damage to the system control.
The typical grounding method is simple (Figure 6-5). A short piece of 12 or 14
gauge copper wire is stripped at each end about two inches. One end is hose
clamped to an absorber plate header. The other end is connected to the collector
frame. The frame connection usually involves the collector mounting hardware.
After installing or reconnecting this ground, use an ohmmeter to make sure there is
a solid electrical connection between the absorber piping and the frame. Cover the
junction between the aluminum frame and the copper wire with silicone sealant to
reduce galvanic corrosion.
At the mechanical room, use the ohmmeter to confirm that the collector loop piping
is connected to ground. If it is not, hose clamp another section of copper wire to the
collector return line. Run this over to a mechanical ground, usually the same one
used for the building electrical system.
Remember that the surface of anodized or painted aluminum does not conduct
electricity. Anodized aluminum may not appear to have any coating.
6.1 MAINTENANCE PROCEDURES