Murphy Digital Loop Monitor MDM45 - Manual

MDM45 Digital Loop Monitor SWICHGAGE ®
Instructions for Installation and Operation
B
®
MDM-9114N
Revised 06-97
Section 05
(00-02-0160)
Description
The MDM45 is a 4-1/2 in. (114 mm) dial digital loop monitor with low and
high trip points which are adjustable over the full range of the monitor. A tog-
gle switch and a push button are provided in the face of the monitor for easy
access to the trip point adjustments. The MDM45 accepts one 4-20 mA trans-
mitter input. It is designed to operate from 12 or 24 VDC systems.
Specifications
Accuracy: ±1.0% of full scale.
Operating Temperature Range: 32 to 155°F (0 to 70°C).
Storage Temperature: -40 to 300°F (-40 to 150°C).
Case Material: Aluminum.
Display Range: -10,000 to 19,999.
Signal Input: 4–20 mA.
Input Resistance: 250 Ohms.
Display Update Time: 0.5 seconds.
Power Input: 1.8 watts @ 12 VDC; 3.6 watts @ 24 VDC.
Trip Point Output: A power FET switch turns on when signal reaches the trip
point. Trip points can be selected to open or close, (0.5 A @ 250 VDC).
* Laboratory Approvals: MDM45 is CSA approved for Class I, Division 2,
Group D, hazardous areas. Digital loop monitor input 10–30 VDC, 4–20 mA.
NOTE: MDM45 is for use with Electromechanical TATTLETALE ® annunci-
ators or SELECTRONIC ® or similar solid-state annunciators.
About Trip Points
During normal operation, both trip points are always active and are indepen-
dent of the trip point selector switch. When the transmitter signal meets the
high or low trip point, that trip point is triggered: the trip point output “turns
on”, and an LED light to indicate the output is ON.
Open Transmitter Input
An open transmitter input causes the SWICHGAGE ® to go negative, trigger-
ing the low trip point if the trip point is being used.
Warranty
A two year limited warranty on materials and workmanship is provided with this
Murphy product. Details are available on request and are packed with each unit.
Mounting
The MDM45 has a flush mount case for installation in a panel from 1/32 in.
(1 mm) to 1/8 in. (3 mm) thick. We recommend to install the MDM45 within a
weatherproof enclosure to protect it from rain, dust, etc.
A round mounting hole size 4-3/4 in. (121 mm) diameter is needed for the
mounting. Three (3) screw holes 1/4 in. (6 mm) are also needed to secure
the unit to the panel (See mounting diagram).
With a straight edge screwdriver remove the three (3) screws located in the
front of the unit and install the unit from the back of the panel; secure firmly
in place by tightening the screws.
NOTE: A minimum distance of 12 in. (305 mm) from any ignition coil or
coil leads should be maintained.
Mounting Dimensions
Please read the following information before installing . A visual inspection for any damage which may
have occurred during shipping is recommended. It is your responsibility to have a qualified person install the
unit, and make sure it conforms with NEC and local codes.
GENERAL INFORMATION
Installation Accessories
● Straight edge screw driver (medium).
● Wire cutters, wire stripping and terminal crimping tool.
● Potentiometer trimmer or small screwdriver with plastic handle.
● 4–20 mA simulator.
● DC power supply (10–30 VDC, 150 mA minimum).
Made in USA
® FRANK W.
MFR.
MDM45
DISPLAY
PUSH TO READ
TRIP POINT
LOW
TRIP PT
HIGH
TRIP PT
®
Approved * for
Class I, Division 2,
Group D Hazardous
Locations
WARNING: Disable the engine (motor) so it can NOT start.
Remove the battery ground cable (when applicable).
1/4 in.
(6 mm)
dia.
3 holes
120
120
120
2-39/64 in.
(66 mm)
radius
Mounting Hole
4-3/4 in. (121 mm)
diameter
panel
side view
WARNING
BEFORE BEGINNING INSTALLATION OF THIS MURPHY PRODUCT
✔ Disconnect all electrical power to the machine.
✔ Make sure the machine cannot operate during installation.
✔ Follow all safety warnings of the machine manufacturer.
✔ Read and follow all installation instructions.