Specifications

P.4.4 Interlocks
The transmitter contains dual contact interlock switches on all rear
doors and on the inner front doors. One set of contacts is used for
the Door Interlock and the other is used for the Control Chain
Interlock. If any of the eight hinged doors are opened both interlock
strings will be broken and the transmitter will be shut OFF.
NOTE
The Power Supply Access Interlock is not used in single transmit-
ter operation.
P.4.4.1 Door Interlocks
Refer to Figure P-1, Simplified Front and Rear Door Interlock
Status String for the following discussion.
P.4.4.1.1 Front Door Interlock String
“Front Door”, in this case, is referring to the Inner doors, inside
the 3 PA compartments. When the transmitter is in the Standy
Mode, +12 VDC is applied thru diode CR12 to the interlock
string at J7-5. When the transmitter is in the Normal Mode, +22
VDC is applied thru diode CR7 to J7-5 and diode CR12 is then
reverse biased. In either case, a voltage is supplied to the interlock
string at J7-5.
When all 3 doors are closed, the voltage will be present at J7-6,
and to the base of Q2 via R46 and R45. This will saturate Q2 and
shut off DS1, indicating all front doors are safely fastened.
When all Rear Doors are also closed and the ground sticks are in
the clip holders, J1-27 will be connected to this voltage and the
transmitter is operational.
If any of the front doors are opened, J7-6 would go low and Q2
will turn off and illuminate DS1 RED. The Door Interlock line
at J1-27 will also go low because the voltage has been removed,
and the Controller will shut OFF the transmitter.
P.4.4.1.2 Rear Door Interlock String
When the Front Door Interlocks are closed, the voltage will be
applied to this string at J7-7. This string includes the 5 rear doors,
both ground stick interlocks, and 4 terminal strip connections. If
all doors are closed and both ground sticks are in place, J1-27
will be high and Q1 will be saturated turning DS2 off.
When a Rear door is opened, the Door Interlock line at J1-27 will
go low shutting the transmitter OFF and Q1 will illuminate DS2
RED.
NOTE
If both a rear door and a front door are open at the same time,
only DS1 will be illuminated. Once the front door is closed, DS1
will shut off and DS2 will then illuminate. Once the rear door is
closed, DS2 will shut off.
P.4.4.2 Control Chain Interlock
Refer to Figure P-2 , Interlock Control Chain for this discussion.
If the External Interlocks have been implemented on the External
Interface, a similar +22/+12 VDC from the External Interface is
Figure P-1. Front & Rear Door Interlock Status String
P-2 888-2339-002
WARNING: Disconnect primary power prior to servicing.