Before working on a solar control's 120 volt wiring, disconnect the
control's power supply. Do not rely on the function switch- in most
controls it does not disconnect the power supply.
Some currently available controls are built with a removable printed circuit card
which can be replaced more easily than the entire control. If the manufacturer and
supplier agree to this procedure, it can be done.
Make sure no strands of sensor wiring are touching adjacent wires or terminals.
Follow the manufacturer's installation instructions carefully. Many controls require
the use or removal of jumper strips for proper operation. When replacing one model
or brand of control with another, be sure the sensors and control are compatible.
Never mix 3K and 10K controls and sensors. System operation and
performance will be seriously affected. See Sections 4.3.1 and 4.3.2
for more information.
Check the control operation, as described in Section 4.3.2 before leaving the site.
5.2.8 Storage Tanks,
If a pressurized tank with a stone or glass lining leaks, it should be replaced. It may
be possible to repair tanks with cement, resin or epoxy linings, but only if
replacement lining is available, and the leak is small enough to be repaired.
If it is necessary to open the manway on a large tank to make repairs, make sure
the tank is purged of all vapors, that it is adequately ventilated and that the nuts or
bolts for the manway hatch go into the tank with the worker.
5.2 REPAIR PROCEDURES