ADA 100
®
Emergency Call System
Housing Devices, Inc.
Page
14
Medford, MA 02155
Copyright © 1998
800-392-5200
PC CARD PROBLEMS
(continued)
RELAY CARD
To test the area Relay Card(s) in the Relay Card Cabinet:
1.
Momentarily short Terminals 1 & 2. You should hear the relay latch.
2.
Select the DC setting on a “Multi meter” and check to see that DC power is present at
the Relay Card Terminal 3, by measuring across Relay Card Terminal 3 (+) and 6 ( - ).
The meter should read +24VDC.
3.
Select the DC setting on a “Multi meter” and check to see that DC power is present at
the Relay Card Terminal 4, by measuring across Relay Card Terminal 4 (+) and 6 ( - ).
The meter should read +24VDC.
If voltages are present:
Shorting Terminal 1 at the Relay Card Cabinet Control Board (+24VDC) with terminal 9
at the respective Relay Card should cause:
•
Terminal 4 to drop voltage to “0” volts
•
Terminal 5 to change to +24VDC
2.
If Terminal 4 does not drop to “0” volts replace the SCR
(see SCR Replacement trouble-shooting section).
3.
If Terminal 5 does not change to +24VDC replace the SCR
(see SCR Replacement trouble-shooting section).
4.
If SCR replacement does not work, please call the Manufacturer.
Note:
The area Relay Card is working properly if all the above items check out as
described.
SCR REPLACEMENT
Each area Relay Card has a removable SCR chip on it located just below the relays. It is
different from the jumper (also located on the area Relay Card between the relays and the
terminal connector).
Two spare SCR chips attached to a mounting screw inside the
Relay Card Cabinet are provided with each system.
The SCR chip is used to switch voltages on Terminals 4 and 5 on the Relay Card from
+24VDC to “0” Volts and back to +24VDC. Use a “Multi meter” to check for the voltage
changes when first trouble-shooting the system. See Relay Card section above. If the
voltages do not switch check the system as follows:
1.
Power down the system.
2.
Unplug the existing SCR chip on the Relay Card, making sure to identify polarity
before removing it. The flat side of the SCR chip should always be facing the
outside edge of the area Relay Card (next to the relays).
3.
Replace with a new SCR chip (making sure to keep the same polarity as previously
stated above).
If the system is still not operational after having tried all of the above listed trouble-
shooting tips please call the Manufacturer.
