Murphy MDM45 specifications Description, Features, Applications, Specifications

Digital Loop Monitor SWICHGAGE®

Model MDM45

MDM-9113B

Revised 01-98

Catalog Section 05

(00-02-0027)

®

Approved*

Approved*

•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.

SWICHGAGE ®

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.