Keri Systems EP1502 - Manual (Page 5)

Mercury Security Corporation © 2011 EP1502 DOC 10107-0031 REV 1.05 Page 5
Input Circuit Wiring (continued):
The input circuit wiring configurations shown are supported but may not be typical:
8. Relay Circuit Wiring:
Four relays with Form-C contacts are provided for controlling door lock mechanisms or alarm signaling.
The relay contacts are rated at 5 A @ 30 Vdc, dry contact configuration. Each relay has a Common pole
(C), a Normally Open pole (NO) and a Normally Closed pole (NC). When you are controlling the delivery
of power to the door strike, the Normally Open and Common poles are used. When momentarily
removing power to unlock the door, as with a mag lock, the Normally Closed and Common poles are
used. Check with local building codes for proper egress door installation.
Door lock mechanisms can generate feedback to the relay circuit that can cause damage and premature
failure of the relay. For this reason, it is recommended that either a diode or MOV (metal oxide varistor)
be used to protect the relay. Wire should be of sufficient gauge to avoid voltage loss.
1K,1%
1K,1%
1K,1%
1K,1%
Standard Supervised Circuit,
Normally Closed Contact
Standard Supervised Circuit,
Normally Open Contact
Unsupervised Circuit,
Normally Open Contact
Unsupervised Circuit,
Normally Closed Contact
Terminal Blocks
TB4 Through TB7
Diode Selection:
Diode current rating: 1x strike count
Diode breakdown voltage: 4x strike voltage
For 12 Vdc or 24 Vdc strike, diode 1N4002
(100V/1A) typical.
MOV Selection:
Clamp voltage: 1.5x Vac RMS.
For 24 Vac strike, Panasonic:
ERZ-C07DK470 typical