204038
Rev. B, 4/12/08
© 2008, THE STANLEY WORKS. ALL RIGHTS RESERVED.
11 of 17
3.9.2
CHECK for correct DC voltage measurements on terminal block assembly as follows:
a.
SET the door to CLOSED/LOCKED.
b.
CONNECT the negative (-) lead of the multimeter to TB2-10 of the DE-MC521
controller.
c.
Refer to Table 3-4, and CHECK each terminal number of the terminal block and
relay assembly for the voltage shown.
Table 3-4. TB2-10 Voltage Checks
DE-MC521
TB2
Terminal
Block and
Relay Assy
Terminal No.
Voltage
Possible Fault if Voltage is Incorrect
TB2-10
0
24 VDC
The bridge on terminal blocks 0-1 or 2-3 is loose. Fire alarm input is
open or missing. The 24 VDC power supply disconnected.
TB2-10
1
24 VDC
The bridge on terminal block 2-3 is loose. Fire alarm input open or
missing.
The 24 VDC power supply disconnected.
TB2-10
2
24 VDC
The bridge on terminal block 2-3 is loose. Check 24 VDC power
supply.
TB2-10
3
24 VDC
The 24 VDC power supply is disconnected.
TB2-10
4
24 VDC
MC521 is selected for Fail Safe. Door position switch is not closed
TB1-7.
TB2-10
5
24 VDC
The bridge on terminal block 0-1 or 2-3 is loose. Fire alarm input open
or missing.
The 24 VDC power supply is disconnected. K1 is defective.
TB2-10
6
24 VDC
The bridge on terminal block 5-6 is loose.
TB2-10
7
0 VDC
Wire connection open from TB5-10. Check if MC521 is configured for
delayed egress.
TB2-10
8
24 VDC
Push bar switch is open. Dual transfer contact is not making
connection. Quad
Contact is not making connection.
TB2-10
9
0VDC
K2 is off.
TB2-10
10
0VDC
Wire disconnected from TB5-4.
TB2-10
11
0VDC
Wire disconnected from TB5-10.
3.10
Replacement Parts
3.10.1
Refer to Attachment 1 for a listing of replacement parts.
