Kipp&Zonen Brewer MkIII - Manual (Page 30)

MKIII SERVICE MANUAL 25
7 AZIMUTH TRACKER
Problems in the Azimuth Tracker affect the Brewer’s ability to track the sun, and thus any
measurement that depends on direct solar radiation may be in jeopardy.
Regardless of the problem, it is usually manifests itself as frequent failures of the Solar Siting test
(SI), or the Steps per Revolution test (SR).
The Main Electronics Board sends motion commands to the Tracker, and receives sensor
indications from the Tracker via the Azimuth Tracker connector on the front of the Brewer base.
Indirect problems can affect Brewer power and communications since both of these cables pass
through the Tracker housing assembly. Communications is routed through a surge suppressor
assembly mounted on the bottom of the Tracker, and Power is supplied to the Brewer via the
Tracker enclosure wherein a second set of surge suppressors is located.
If the surge suppressors in the communications line are faulty, a no-communications condition can
exist. The communication cable from the Computer can be connected to bypass the Tracker as a
troubleshooting aid in determining if the surge suppressor assembly is at fault.
Similarly, power can be connected directly to the Power Connector on the Brewer in the event that
a “no power” problem exists in the Brewer.
The Power switch on the Tracker will not affect power to the Brewer, but a failure of the fuse in the
Tracker will interrupt both Brewer and Tracker power.
Tracker problems can be either mechanical or electrical.
7.1 BREWER POWER PROBLEMS.
Power for the Brewer passes through the Tracker Case where it is connected to a set of MOV
surge suppressors. In the event of large transient voltages on the power cable, one or more of
these components may become damaged, and subsequently result in AC power short circuits
which may affect power to both the Brewer and the Tracker. Connecting the AC power directly to
the Brewer and observing if operation is restored is a method of troubleshooting this subassembly.
An ohmmeter can then be used to determine the specific component at fault. Power connections in
the Tracker, including the Fuse, can also be checked in the event of power problems in the Brewer.
7.2 BEWER COMMUNICATIONS PROBLEMS
A failure in the surge suppressor in the communications link can be checked by connecting the
communication cable from the Computer directly into the Brewer. If Brewer/Computer
communications are restored, the surge suppressor subassembly is likely at fault.
7 AZIMUTH TRACKER