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Morrison Bros. Co. ‑ Dubuque, IA ‑ 800‑553‑4840
918S‑‑1130 PP rev 12‑21‑2020
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918S Single Channel Alarm
The 918S is designed to provide a visible and audible alarm. The 918S may be used anywhere that a single
set of dry contacts are available. The 918S can be configured to respond to either Normally Open (default
configuration) or Normally Closed contacts. Two possible primary applications are used as an overfill alarm or
as an interstitial alarm.
918D Dual Channel Alarm
The 918D is designed to provide a visible and audible alarm. The 918D has two front panel Alarm Indicators to
indicate which channel is being alarmed. The 918D may be used anywhere that up to two sets of dry contacts
are available. The 918D can be configured to respond to either Normally Open (default configuration) or
Normally Closed contacts. Two possible primary applications for each channel are as an overfill alarm or as an
interstitial alarm.
918Q Quad Channel Alarm
The 918Q is designed to provide a visible and audible alarm. The 918Q has four front panel Alarm Indicators to
indicate which channel is being alarmed. The 918Q may be used anywhere that up to four sets of dry contacts
are available. The 918Q can be configured to respond to either Normally Open (default configuration) or
Normally Closed contacts. Two possible primary applications for each channel are as an overfill alarm or as an
interstitial alarm.
Failure to follow any or all of the warnings and instructions in this document could result in a hazardous
liquid spill, which could result in property damage, environmental contamination, fire, explosion, serious
injury or death.
Le fait de ne pas se conformer à l’un ou l’autre des avertissements ou à l’une ou l’autre des directives
apparaissant dans ce document pourrait donner lieu à des déversements de liquides dangereux, lesquels
pourraient engendrer des dommages matériels, des risques de contamination environnementale,
d’incendie ou d’explosion, des blessures graves ou la mort.
Specifications
The 918S, 918D and 918Q are intrinsically safe devices for use in Class I, Division 1, Group D, T4 and Zone 2,
Group IIA, T4 Hazardous locations when powered by Morrison Bros. Co. battery pack part number
918SB-0128 2B.
WARNING:
This is an intrinsically safe device and must be wired in accordance with National Electrical Code
Article 504. This device and its wiring may not share any junction box, conduit, or raceway with any other type
circuit or wiring. Do not perform live maintenance. Do not substitute components with anything other than
Morrison Bros. Co. components. Care must be taken to avoid an ignition hazard from impact or friction with the
enclosure.
AVERTISSEMENT:
Cet appareil intrinsèquement sécuritaire doit être branché conformément à l’article
504 du code électrique national. Il se peut que ce dispositif et son câblage ne partagent pas de boîte de
connexion, de conduit ou de canalisation avec un autre type de circuit ou de câblage. Ne menez pas de travaux
de maintenance sous tension. Ne remplacez les composantes que par des composantes de Morrison Bros. Co.
Assurez-vous d’éviter le risque d’infl ammation pouvant découler d’un impact ou de friction avec l’enceinte.
Entity Parameters for Terminals P1 through P4:
Operating Temperature: -40ºF to 140ºF (-40ºC to 60ºC)
Maximum Wiring Distance: Maximum wiring distance between Alarm and input device is 500 ft.
918S, 918D, and 918Q Series Alarms
Installation, Operation, and Maintenance Instructions
V
OC
= 7.525 VDC
I
SC
= 31 mA Ca = 700 μF La = 105 μH P
O
= 0.06 W
