Regency 4720 - Contact Wiring Methods for Internal Zones; Wiring Smoke Detectors to Internal Zones

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Regency

Model 4720 Control/Communicator Installation Manual (P/N 150476, Rev. A) Revised 10/98

9.1 Normally Open and Normally Closed Contact Wiring

* Supervision of either N.O. or N.C. contacts is optional (see the Model 4720 Programming Options

Description Manual, P/N 150299).

Note 1: When supervising normally open contacts, a 15-kΩ end-of-line resistor must be used.

Note 2: When using normally closed contacts, a 15-kΩ resistor must be installed in series with the loop.

Note 3: When using a combination of contacts, a 15-kΩ resistor must be installed in series with the normally closed

contacts and in parallel with the normally open contacts.

Note 4: For UL installations, minimum wire gauge is 18 or larger (i.e., #16, #14, etc.). Maximum loop wiring

resistance is 250 Ω.

Figure 9.1a: Internal Zone Wiring

9.2 Smoke Detector Wiring

The ESL 445AT 12-V

, 4-wire Smoke Detector must be used when wiring fire zones on the Model 4720

in a UL installation. Refer to NFPA 72E for proper smoke detector placement. Figure 9.2 shows how to

wire the 445AT Smoke Detectors ESL 445AT. The ESL 445AT Smoke Detector is rated at 1.5 mA in the

normal supervisory condition and 60 mA in the alarm condition. Refer to Table 4.1.1.0a for the maximum

number of detectors that may be used. The ESL 204A Power Supervision Unit and Model 7630 EOL

Resistor must be mounted across the last detector in the loop.

Note 1: If you want to use more than seven (7) smoke detectors, connect Terminal 1 of the smoke detector to

Terminal 3 or 4 of the Model 4195 Auxiliary Power Supply (instead of Terminal 10 of the Model 4720),

and connect Terminal 6 of the Model 4195 to Terminal 10 (instead of Terminal 5) of the Model 4720. When

the Model 4720 powers up, Terminal 10 of the Model 4720 will drop to 0 V

momentarily, which will

reset all the smoke detectors. In this configuration, a maximum of 20 smoke detectors may be used.

Note 2: Two-wire smoke detectors can NOT be used with the Model 4720, unless the Model 7181 Fire Zone

Converter is installed (see Section 9.3).