Keri Systems EP1501 - Manual (Page 7)

Mercury Security © 2014 EP1501 DOC 10107-0036 REV 1.07 Page 7
TB5
2-C
NC
NC
NO
1
NO
1-C
9. Relay Circuit Wiring:
Two Form-C contact relays are provided for controlling door lock mechanisms or alarm signaling devices.
The relay contacts are rated at 2 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 EMF 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.
From the Auxiliary output, the EP1501 can provide 12 Vdc power for external devices provided that the
maximum current is not exceeded. See the specifications section for details. If a local power supply is
used, it must be UL Listed Class 2 rated.
Relay Circuit Wiring Diagrams:
10. Memory Backup Battery:
The SRAM is backed up by a rechargeable battery when input power is removed. This battery should
retain the data for a minimum of 3 days. If data in the SRAM is determined to be corrupt after power up,
all data, including flash memory, is considered invalid and is erased. All configuration data must be re-
downloaded.
Note: The initial charge of the battery may take up to 48 hours to be fully charged.
Diode Selection:
Diode current rating: 1x strike current
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.
Use UL recognized MOV with appropriate
ratings
TB5
1
NO
1-C
NC
NC
NO
2-C