Bird Technologies 8630B Series - Manual (Page 37)

Maintenance
21
Repair
The series 8630 and 8631B, 8635 and 8635B, 8638 and 8638B loads
are designed for independent, long term, trouble-free operation.
Regular mechanical maintenance procedures, other than routine
checks and cleaning care described previously, are not required. In
the case of malfunction of the unit or replacement of a major
component, resistor repair excepted, the entire load may be returned
to the factory. This applies especially to any unit still under the one
year warranty. Consult the factory.
Note: Do not tamper with operational settings or perform other
unauthorized maintenance work during the first year. It could be cause
to void the warranty.
Field repair of the load resistor may be performed as described in the
Internal Repair of the Load Resistor paragraph. Other replacement
instructions that might be needed are given in this section.
If in performing the DC resistance check a significant change in
resistance is noted, or if for any reason the resistive element should
fail, the element should be replaced. Inexpensive replacement
resistors are available. Installation is described below.
RF Load Resistor
Unit Removal
Resistor repair in the load may be done without removing the water
connections; follow procedures in the Internal Repair of the Load
Resistor paragraph. They contain full dismounting and resistor
change procedures. The full load assembly may be removed from the
case as in the following procedure. Then follow the Internal Repair of
the Load Resistor section.
Note: Notice the angular position of all elbows and associated
parts as they must be returned to relatively the same position
when reassembled.
1. Turn off RF power and interlock circuitry before any electrical
disconnections are made.
2. Disconnect the RF coaxial line.
Models 8631 / 8631B and 8635 / 8635B — flanged, loosen and
remove the 3/8-16 bolt and nut sets that secure the flanges. Refer
to Figure 4.
WARNING
Never attempt to connect or disconnect an RF cable while power is on at
the RF power source. Radiated RF energy is a potential health hazard.