Edwards Signaling 879DEX User Manual

Edwards Signaling Safety

Installation Instructions for Explosion-Proof

Adaptahorn Catalog Series 878DEX and 879DEX

Description and Operation

Edwards explosion-proof Adaptahorn signals, catalog num-
bers 878DEX-N5 and 879DEX-G1, are heavy-duty vibrating
horns intended for use where distinctive audible signals
are required in a hazardous location having high ambient
noise levels.

These horns include a series diode and are suitable for use
in applications requiring electrical supervision of signal-
ing circuit installation wiring.

The 878DEX-N5 is ac powered and the 879DEX-G1 is dc
powered. Both AdaptaHorn signals are listed for installa-
tion in the following hazarouds locations: Class I, Divi-
sion 1 and 2, Groups B, C, and D; and Class II, Division 1
and 2, Groups E, F, and G and Class III locations. The
horns are in a outdoor type 4X rated enclosure (outdoor
type 4X applies to general signaling use in non-fire alarm
applications). The Adaptahorn may be mounted to any
solid surface.

Electrical Specifications

•

One explosion-proof conduit outlet box suitable
to the hazardous location

•

One 3/4-14 National Pipe Taper (NPT) nipple
connectors.

•

Two fasteners up to 3/8" diameter and washers
suitable for securing the horn to mounting surface.

The horn may be mounted to any solid surface. Install
the unit as follows:

See Figure 1. Remove the cover from the conduit
outlet box. Feed the two power supply wires from
control panel or previous signal and the two wires to
next signal or end-of-line device through conduit into
the outlet box. Also, feed the horn's four wire leads
through the nipple, which connects the horn to the
outlet box, into the box. Secure the horn, nipple and
conduit to the outlet box.

Catalog

Rated

Alarm

dBA Rating

Number

Voltage

Current (A)

at 10 ft.

878DEX-N5

120V AC

0.165A

879DEX-G1

20-24V DC

0.16A

CAUTION

Do not apply power to the unit until installation is
completed and cover is secured.

With horn placed against mounting surface, mark
mounting hole positions for fasteners as per Figure 1.
Install fasteners with washers through mounting
brackets and secure unit to surface.

In the outlet box, connect the installation wiring to
the horn's wire leads using wire nuts (Figure 2 or 3).
Replace cover on outlet box.

Apply power to the system control panel. Initiate an
alarm to activate the horn and verify that it sounds.
Reset the panel to silence the horn and return system
to the supervisory mode.

Maintenance and Test

Examine the unit periodically for accumulation of dirt.
Clean if necessary.

The Adaptahorn should be tested monthly or at the inter-
vals required by applicable fire regulations to ensure con-
tinuous service.

Ambient Temperature:

The UL Hazardous Locations Listing is “only for use under
normal atmospheric conditions in an ambient tempera-
ture within the range of -25C (-13F) to +40C (+104F)”; and
within these ambient temperatures, Edwards recommends
+25F (-4C) and higher for its function as an audible signal
appliance.

Installation

For power connections in a hazardous location, the fol-
lowing external parts will be required (not supplied):

•

3/4 inch conduit of sufficient length to contain
power source wires within hazardous location

Cheshire, CT 06410 203-699-3300 (Ph)
203-699-3365 (Cust. Serv. Fax)
203-699-3078 (Tech. Serv. Fax)

This manual is related to the following products:

878DEX