Mercury Security © 2015
EP4502
DOC 10107-0039
REV 1.02
Page 5
8. Input Circuit Wiring:
There are 8 inputs that are typically used to monitor door position, request to exit or alarm contacts. Input
circuits can be configured as:
Unsupervised alarm (2 states); reporting as open or closed contact.
Supervised alarm (6 states); reporting as open or closed contact, open circuit, shorted circuit, grounded
circuit *, or foreign voltage*.
A supervised input circuit requires adding two resistors with value of 1k ohm, 1% to the circuit to facilitate
proper reporting and should be located as close to the sensor as possible. Custom end of line (EOL)
resistances may be configured via the host software.
* Grounded and foreign voltage states are not a requirement of UL 294 and therefore not verified by UL.
The input circuit wiring configurations shown are supported but may not be typical.
9. 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 a diode 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 current
Diode breakdown voltage: 4x strike voltage
For 12 Vdc or 24 Vdc strike, diode 1N4002
(100V/1A) typical.
