Keri Systems MR51e User Manual

Page 4

MR51e

DOC 10107-0035

REV 1.05

Page 4

7. Input Circuit Wiring:

Typically, these inputs are used to monitor door position, request to exit, or alarm contacts. Input circuits
can be configured as unsupervised or supervised. When unsupervised, reporting consists of only the
open or closed states.

When configured as supervised, the input circuit will report not only open and closed, but also open
circuit, shorted, grounded*, and foreign voltage*. A supervised input circuit requires two resistors be
added to the circuit to facilitate proper reporting. The standard supervised circuit requires 1K Ohm, 1%
resistors 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:

8. Relay Circuit Wiring:

Two Form-C contact relays are provided for controlling door lock mechanisms or alarm signaling. The
relay contacts are rated at 5 A @ 30 Vac/dc, 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 you are
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%

Standard Supervised Circuit,
Normally Closed Contact

Standard Supervised Circuit,

Normally Open Contact

Unsupervised Circuit,
Normally Open Contact

Unsupervised Circuit,
Normally Closed Contact

TB
2

IN4

IN2

IN3

IN1

TB
1

}