CM4 Four-Point Continuous Monitor
CM4 Technical Manual
3-12
3.10 Wiring Relays
This section describes relay:
• Contacts
• Ratings
• Wiring guidelines
WARNING
Use caution when servicing fuses or terminal blocks. Power to
contacts is supplied externally.
3.10.1 Relay Contacts
The CM4 has 13 form C, single-pole, double-throw relays that activate
external alarm devices. Contacts are available for each circuit to
accommodate installation of external devices.
The relay panel may be removed from the CM4 chassis without
disconnecting relay wiring. This allows you to replace the CM4 without
having to reinstall the relay connections.
Each relay has three terminal contacts.
• Normally open
• Fused common
• Normally closed
The terminal blocks for the relay contacts are located on the relay
panel. See
. Relays include:
•
Four Level 1 alarms (RY1, RY3, RY5, RY7)
•
Four Level 2 alarms (RY9, R11, RY13, RY14)
•
One general Level 1 alarm (RY2)
•
One general Level 2 alarm (RY4)
•
One watch dog (power loss/CPU failure) relay (RY12)
•
One maintenance fault relay (RY8)
•
One instrument fault relay (RY10)
•
One “Out of Monitoring” relay (RY6)
NOTE:
Make sure that watch dog relays and instrument fault relays are
wired in series to ensure that any fault will trigger a diagnostic
alarm. This will ensure a fail-safe operation.
1
2
Table and Rack Mount
Wall Mount
Figure 3-10: Relay Panel (Cover Removed)
Legend
1
I/O panel (cover removed)
2
Route relay wiring through
knockouts as required
3.10.2 Ratings
To ensure reliable contact operation, the following limits must be
observed:
• 0.1 to 2.0 amps
• @5-24 VDC or
• @5-120 VDC
CAUTION
The alarm relay has a minimum load requirement of greater than 5V
and 100 mA. For reliable relay operation, ensure the alarm circuit
meets these requirements.
The relay contacts are protected by metal oxide varistors rated for
120 VAC maximum operation.
珠海司福斯特科技有限公司
www.safedtech.com