Murphy MDM45 Switch User Manual


 
Description
Model MDM45 is an electronic LOOP MONITOR which
accepts one 4–20 mA transmitter input and digitally dis-
plays the results via a highly visible Liquid Crystal Display.
Separately adjustable high and low limit trip points are also
provided for control functions. A toggle switch and push but-
ton on the face allow the operator to select the trip point to
be read and set. Both trip points are always active regard-
less of the position of the toggle switch.
Designed to be installed within a weatherproof enclosure the
MDM45 can be panel mounted in the same manner as our
popular OPL and SPL series SWICHGAGE
®
instruments.
Zero and span adjustments are easily accessible from the
face of the MDM45 for setting to the 4–20 mA input signal.
Features
The model MDM45 is designed to operate from 12 or 24
VDC (10-30 VDC) systems. This model has FET trip point
outputs. The “Push to Read” button allows the operator to
check each trip point value and to watch the display as
adjustments are made to a selected trip point. Releasing the
push button returns the readout to that equal to the input
signal: i.e. pressure, level, percent open, etc. The user
determines the unit of measurement according to the source
of the input signal. An LED below the trip point adjustment
potentiometer lights to indicate that the trip point has been
reached.
Added value from basic features. (1) Onboard DC to DC
conversion for superior interference isolation. (2) Front
accessible span and zero adjustment. (3) Easy to read one-
half inch numerals on a liquid crystal display. (4) Three instru-
ments in one: digital gauge, low limit switch, high limit switch.
(5) Extremely user friendly and highly field adaptable.
Applications
Engine/compressor lube-oil pressures
Pump/compressor discharge pressures
Valve position indication (% open/closed)
Vibration
Any 4–20 mA input
Specifications
Accuracy: ± 1% of full scale.
Operating Temperature Range: 32 to 155°F (0 to 70°C).
Storage Temperature: -40 to 300°F (-40 to 150°C).
Display Range: -10,000 to 19,999.
Signal Input: 4–20 mA.
Input Resistance: 250 Ohms.
Display Update Time: 0.5 seconds.
Power: 1.8 watts @ 12 VDC
3.6 watts @ 24 VDC.
min.-max. operating voltage 10–30 VDC.
Trip Point Output: A power FET switch turns on when
signal reaches the trip point. Trip points can be selected
to open or closed (0.5 amp @ 250 VDC).
Shipping Weight: 2 lb. 7 oz. (1.2 kg).
Shipping Dimensions: 10 x 9 x 6 in. (254 x 229 x 152 mm).
Laboratory Approvals: CSA and FM approved
for Class
I, Division 2, Group D, hazardous locations).
Approved for 10–30 VDC power input and 4–20 mA signal input.
About Trip Points
During normal operation, both trip points are always active
and are independent 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 lights to indicate the output is ON.
MDM-9113B
Revised 01-98
Catalog Section 05
(00-02-0027)
Digital Loop Monitor SWICHGAGE
®
3 Instruments in 1
Monitor Any 4–20 mA
Linear Output
Designed to Operate
from 12–24 VDC
Adjust a Separate Trip Point
for High and Low Values
Easy Access for Trip Point,
Span and Zero Adjustments
Specify Unit of
Measurement
*
Approved for 10–30 VDC power input and
4–20 mA signal input.
Model MDM45
SWICHGAGE
®
®
Approved
*
Approved
*