3
Morrison Bros. Co. ‑ Dubuque, IA ‑ 800‑553‑4840
918S‑‑1130 PP rev 12‑21‑2020
WARNING:
Interconnect wiring between the gauge and the alarm unit must be kept totally isolated and separate
from any other wiring. This wiring must not share any junction box, conduit, raceway, or fixtures with circuits
other than those defined by NEC as being intrinsically safe for all Class 1 locations.
AVERTISSEMENT:
Le câblage d’interconnexion entre la jauge et l’unité d’alarme doit être complètement
isolé et distinct du reste du câblage. Le câblage ne doit partager aucune boîte de connexion, aucun conduit,
aucune canalisation, ni aucun accessoire avec des circuits autres que ceux défi nis par NEC comme étant
intrinsèquement sécuritaires pour tous les emplacements de classe 1.
Location:
NEC ARTICLE 501-3-CLASS 1 Locations exempt intrinsically safe enclosures in paragraph
501-3(b)(1)(c), and therefore may be placed in the most convenient location but must be within reach of the
operator and within audible range.
Mounting:
Since a general purpose NEMA 4X enclosure is used to protect the alarm circuits and batteries,
any mounting holes, conduit, or fasteners must be sealed in order to maintain the waterproof integrity of the
enclosure. All penetrations into the enclosure must be made at the bottom of the Alarm Box.
Steps
1. Wire Input Device
a. Run two
stranded conductor
oil and gas resistant wires from each input device to the location where
the alarm box will be mounted. Do NOT attach the wires to the wires in the junction box of the input
device(s) at this time. Although not required, it is recommended to run the wires in some type of conduit
in order to protect them against possible damage and environmental conditions. It may be necessary to
remove the junction box cover of the input device(s).
INPUT DEVICE WIRING WIRE SIZE LIMITS:
Input device wiring shall have a minimum cross section of 0.4 mm
2
(equivalent of a single 26 AWG wire)
to a maximum cross section of 1.0 mm
2
(the equivalent of a single 18 AWG wire).
b. Do NOT attach the wires to the wires in the junction box of the input device at this time.
2. Mount the Alarm
a.
Separate
the two halves of the Alarm Unit box by loosening the Phillips head fasteners visible at the four
corners of the front panel.
b.
Support
the front panel while mounting the rear half.
c.
Attach
the rear half of the box to a suitable fixture.
d.
Seal
any penetrations made into the interior of the box to prevent moisture ingress.
3. Test the Alarm.
a.
Turn on
the power switch, SW5 (see Figure 1).
b.
Press and hold
the “Test/Cancel” button until the alarm sounds at least three times while observing the
Channel Alarm and BATTERY LOW Indicators (see Figure 1).
c.
Observe
the 918 Series Alarm indicates the following:
• The BATTERY LOW indicator will flash momentarily at the beginning of the cycle.
• If the Audible Alarm is configured to sound with an alarm condition, it is loud and strong.
Fig. 1 Power Switch (SW5) ... Channel Alarm Indicators, Battery Low Indicator
and Test/Cancel Button on the 918D
SW5
ON
OFF
Channel Alarm
Indicators
Low Battery
Indicator
Test/Cancel
Button
