When in the non-alarm state:
• The impedance between the NC and C contacts is open circuit
• The impedance between the NO and C contacts is less than 40Ω
When the GridTime 3000 is powered down:
• Same impedances between contacts as the alarm state
• The impedance between the NC and C contacts is less than 40Ω
• The impedance between the NO and C contacts is open circuit
Figure 6-17. Alarm Relay Port States
Non-alarm state relay 1,
Non-alarm state relay 2
Relay 1:
NC-C open circuit
C-NO closed circuit
Relay 2:
NC-C open circuit
C-NO closed circuit
NC
C
NO
NC
C
NO
Alarm state relay 1,
Non-alarm state relay 2
Relay 1:
NC-C closed circuit
C-NO open circuit
Relay 2:
NC-C open circuit
C-NO closed circuit
NC
C
NO
NC
C
NO
Non-alarm state relay 1,
Non-alarm state relay 2
Relay 1:
NC-C open circuit
C-NO closed circuit
Relay 2:
NC-C closed circuit
C-NO open circuit
NC
C
NO
NC
C
NO
Alarm state relay 1,
Alarm state relay 2
- or device powered down
Relay 1:
NC-C closed circuit
C-NO open circuit
Relay 2:
NC-C closed circuit
C-NO open circuit
NC
C
NO
NC
C
NO
Cable Recommendations
• Use a cable terminated with a six-pin phoenix connector with locking screws
• Ensure the cable is rated for expected current from the end device
Connection Recommendations
:
• Use an in-line resistor or load which draws a safe current amount. This will ensure excessive current isn’t drawn
when a pair of contacts is in the low impedance state
• Use a circuit breaker with twice the rated current to protect the relay port and the connected end device
• Apply an external source of power to monitor whether current is passing through the relay
• For a normally closed alarm configuration, plug the cable’s 2 pin connector into the NC and C contacts
• For a normally open alarm configuration, plug the cable’s 2 pin connector into the NO and C contacts.
CAUTION
In case of fire or electric shock, cut-off power at circuit breaker
Equivalent Circuit Diagrams
Connect the alarm relay and the external components for a normally closed or normally open configuration as per the
equivalent circuit diagrams in
Alarm Relay Recommended Circuit Configuration
Installation
©
2022 Microchip Technology Inc.
and its subsidiaries
Manual
DS00004572A-page 50
