Morrison Bros. co. 925 Series Installation & Maintenance Instructions

925 Series Multi-Level Sensors
Installation & Maintenance Instructions
The 925 detects the level(s) of liquid in a tank when used in conjunction with an alarm device like the Morrison
Figures 918S, 918D, 918Q or 918AC. Once the liquid has reached the level of actuation, the sensor will send
a signal causing the alarm, to which the sensor is connected, to be activated. The 925 may be ordered with 1-5
user specified set points for the level floats.
!
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.

Installation

! WARNINGS
• Fire Hazard – Death or serious injury could result from spilled liquids.
• Any modification of this sensor other than those stated in these installation instructions will void the product
warranty.
• This device is intended to be used as an auxiliary warning to the operator of a possible alarm condition and
should not be the only system in place to prevent a tank from overfilling. It is the sole responsibility of the
operator to continuously prevent any spillage regardless of the situation or status of the sensor.
• Install in accordance with all applicable local, state, and federal laws.
• For your safety, it is important to follow local, state, federal and/or OSHA rules that apply to working inside,
above, or around the storage tank and piping area. Use all personal protective equipment required for working
in the specific environment.
• Tanks could be under pressure. Vapors could be expelled from tank vents, piping, valves or fittings while
performing installation. Vapors could catch fire or cause an explosion. Avoid sparks, open flame, or hot tools
when working on gauge.
• In the event of malfunction, contact Morrison Bros. Customer Service.
Electrical Switch Ratings
100 watt resistive load, 300VAC-700mA max / 350VDC - 1.0A max, SPST (Ratings for resistive loads only.)
*Do not use for inductive loads.

Wiring

NOTE: As defined in article 501 – Class 1 Locations of the National Electric Code, this apparatus and its
connected wiring are intrinsically safe. Under normal conditions this apparatus and its wiring cannot release
sufficient energy to ignite a specific ignitable atmospheric mixture by opening, shorting, or grounding.
Important: Wiring must be performed by a qualified technician, licensed by the appropriate local, state, and
federal authority. All appropriate precautions and electrical codes should be followed.
WARNING: Interconnect wiring between the Sensor and its destination must be kept isolated and separate
from 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.
NOTE: The 918S, 918D and 918Q alarm boxes are intrinsically safe devices for use with Class 1, Division L
Group D. T4 Hazardous locations when powered by Morrison Bros. Co. battery pack part number 918S--0113 2B.
8-13-18
Level Wire Color
L5 Blue
L4 White
L3 Yellow
L2 Black
L1 Red
Morrison Bros. Co. ‑ Dubuque, IA ‑ 800‑553‑4840
1
925S‑‑0115 PP