Bird Technologies 8630B Series - Manual (Page 47)

Maintenance
31
proper place. If the resistor seems to be loose, refer to the
procedure for the replacement of fractured resistors or damaged
internal parts below for instructions on how to tighten the resistor
fitting.
3. If damaged, replace the inner flow tube. If undamaged, place the
original flow tube inside the resistor and lower it until it reaches
the resistor fitting. Gently work and twist the inner flow tube until
it seats in the bottom of the resistor fitting.
4. Place the resistor ground cap on the exposed end of the resistor,
and press it into place. Slide the O-Ring down the inner flow tube
until it rests on the end of the resistor.
5. Slide the retainer sleeve down the inner flow tube until it rests on
the O-Ring, ensuring that the end of the retainer sleeve with the
larger inside diameter goes on first.
6. Check the O-Ring inlet seal to see that it is properly seated in its
groove in the inside of the water chamber subassembly.
Note: Normally, the water chamber will not have been dismounted. Be
sure the screws are removed from the flange connecting the outer
conductor assembly.
7. Place the resistor housing through the front panel opening, and
into the water chamber. Gently turn the housing clockwise to
thread it on, eventually bottoming it in its original position.
8. Reverse the procedure of the RF Load Dismounting paragraph, to
restore the original condition. Do not replace the top panel until
after this section is completed.
9. Check the DC resistance between the outer and inner conductors;
it should be approximately 50 ohms. Refer to the Measure DC
Resistance section, and Figure 7.
10. If the resistance check passes, fill the unit with coolant,
performing the flush out procedures of the RF Load Dismounting
section, and check for leaks.
Note: After the completion of this or any of the resistor repair
procedures, perform a 10 kW test on the ac line power. Perform this test
with the Moduload unit in operation for at least one-half hour, and check
the DC resistance before RF load use.
Replacement of Fractured Resistor or Damaged Internal Parts
Resistor Removal The load should already be disassembled to the point of the Resistor
Removal section, step 5.