Herrtronic
®
MD Series
I n s t a l l a t i o n , O p e r a t i o n , & M a i n t e n a n c e M a n u a l
26
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Summary of Troubleshooting Tips for the Inputs and Outputs of the EST-1250 Circuit Board
Turn power ON to the unit (green power light should be ON) & verify proper sensor installation. If all of the 24 VAC inputs to the
circuit board are energized, but ANY of the outputs from the circuit board are NOT indicated, the circuit board may not be operating
properly.
1) Verify that these inputs to the circuit board are energized:
24 VAC Input to Board
Source of 24 VAC Input to Board
At Connector J3
At Terminal Block
PIN 1, wire # 17
Terminal 10, wire # 17
PIN 4, wire # 18
Terminal 9, wire # 18
PIN 8, wire # 19
Terminal 8, wire # 19
PIN 10, wire # 20
Terminal 7, wire # 20
At Connector J5
At Terminal Strip
PIN 1, wire # 37
Terminal 3, wire # 16 (thru door interlock)
PIN 2, wire # 45
Terminal 2, wire # 45
At Connector J5
At Auxiliary contact
PIN 3, wire # 3
Wire # 3
2) Verify that these outputs from the circuit board are energized:
24 VAC Output from Board
Function of 24 VAC Output from Board
At Connector J3
PIN 5, wire # 34
Energize contactor coil, wire # 34
PIN 9, wire # 23
Energize drain solenoid, wire # 23
PIN 11, wire # 13
Energize fill solenoid, wire # 13
DC Output from Board
Function of DC Output from Board
At Connector J5
At Terminal Strip
5 VDC at PIN 5, wire # 5
5 VDC available at terminal #10, wire # 5
20 VDC at PIN 8, wire # 8
20 VDC to power sensors from terminal #7, wire # 8
5 VDC at PIN 9, wire # 9
5 VDC to simulate sensor input at terminal #6, wire # 9
Output to Unit Display
From Connector J4
Board generates clear and legible two line display instead of a single row of black or gray blocks.
