Continental Electronics 816R - 816 R Phase Loss Wiring Modification; Modification Procedure

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816R PHASE LOSS WIRING MODIFICATION
The phase loss/low voltage sensor circuits in the 816R transmitters are intended to protect the three phase blower and fan
motors by removing all primary line voltage frrm the motors if the line voltage is too low or if there is a missing phase.
This is accomplished by interrupting the 28 volt control voltage. These circuits function reliably when only filament
control is on. However, there is a possibility that a “ sneak" path through QI on the Power Monitor/Control module, A2A6.
can bypass these phase loss protection circuits when plate control is ON and may damage the three phase motors if one
phase is missing or if the line voltage is low.
Modification Procedure
Using the drawing below, locate relays A8K5 and A8K7 in your transmitter. There are three wires on terminal 8 of the
orange colored phase loss relay K5. Move the white wire with brown tracer and the green wire to terminal 8 of relay K7.
There should be one solid white wire still connected to terminal 8 of K5. This completes the modification.
Check for proper operation by turning just filament control ON and adjusting the Phase Loss adjustment that is located on
K5 in a clockwise direction until the indicator lamp on K.5 goes OFF. The blower and filament control should go OFF at
this time. Rotate the phase loss threshold adjustment counterclockwise until the indicator lamp K5 comes ON. It should
now be possible to turn the filament and plate control ON. With plate control turned ON, adjust the phase loss threshold
adjustment in a clockwise direction until the indicator lamp on K5 goes OFF. Filament and plate control should go OFF at
this time also. Adjust the phase loss threshold adjustment on K5 fully counterclockwise. Tliis completes the check.
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