Brochure

The performance specifications are nominal and conform to acceptable industry standards. For applications at conditions beyond these specifications, consult the local Johnson Controls office.
Johnson Controls, Inc. shall not be liable for damages resulting from misapplication or misuse of its products. © 2015 Johnson Controls, Inc. www.johnsoncontrols.com
R-56
MR Series Defrost Control Modules
Description
The MR Series Controls are versatile,
microprocessor-based, multifunction,
programmable temperature controls.
Depending on the model chosen, the
MR Series Controls can also manage alarm,
defrost cycle (active or passive defrost), and
evaporator fan functions.
The MR Series Controls have large red LED
displays. These compact controls are
available in panel mount and DIN rail mount
varieties. The MR Series Controls use the
A99B temperature sensors, which allow
remote mounting of the display unit.
All MR Series Controls perform temperature
and alarm management. Some models have
additional capabilities.
MR1 Series Controls
The MR1 Series provides temperature and
alarm management functions. It can replace a
temperature control and digital temperature
readout.
MR2 Series Controls
The MR2 Series provides temperature, alarm,
and defrost cycle management. The MR2
control performs defrost cycle management
using time-based, passive, off cycle defrost. It
can replace a temperature control, a digital
temperature readout, and a defrost timer.
Refer to the MR Series Refrigeration
Temperature Controls Product Bulletin
(LIT-125199) for important product
application information.
MR4 Series Controls
The MR4 Series provides temperature, alarm,
defrost, and evaporator fan management.
The MR4 Series provides defrost cycle
management with hot gas or electric heat
defrost and defrost termination based on time
or temperature. The MR4 Series consolidates
the functions of a temperature control, a
digital temperature readout, a defrost cycle
timer, and a defrost termination device.
Refer to the MR Series Refrigeration
Temperature Controls Product Bulletin
(LIT-125199) for important product
application information.
Features
• programmable functions allow adjustment
of control settings to meet application
needs
• alarm management functions provide local
alarm display and an alarm output relay
that can be used to trigger a remote alarm
or dial-out modem
• easily readable LED display displays
temperature and other functions quickly
and clearly
• programming button lockout allows user to
disable programming buttons and deter
accidental or unauthorized changes
• accurate, interchangeable temperature
sensor provides accurate control
performance with up to 300 feet of wiring
(an adjustable temperature offset is
provided for longer wiring)
• self-test procedure checks control
operation by cycling all outputs and testing
all LEDs
Applications
Application MR1 MR2 MR4
Cooling tower pump control 
Space and return air temperature control 
Convenience store coolers 
Convenience store freezers 
Supermarket display cases for produce 
Reach-in coolers 
Walk-in coolers 
Freezers or coolers with passive defrost,
time-based termination

Freezers with hot gas defrost
(temperature or time-based termination

Freezers with electrical defrost
(temperature or time-based termination)

Selection Chart
Product Code
Number
Description Ship. Wt.
lb (g)
MR1DR24-11C MR1 Single-Stage, DIN Rail Mount Defrost
Control, One A99BB-200C sensor included
0.75 lb
(340 g)
MR2PM24-11C MR2 Two-Stage, Panel Mount Defrost
Control, One A99BB-200C sensor included
0.53 lb
(240 g)
MR2DR24-11C MR2 Two-Stage, DIN Rail Mount Defrost
Control, One A99BB-200C sensor included
0.79 lb
(360 g)
MR4PM24-12C MR4 Four-Stage, Panel Mount Defrost
Control, Two A99BB-200C sensors included
0.90 lb
(410 g)
MR4DR24-12C MR4 Four-Stage, DIN Rail Mount Defrost
Control, Two A99BB-200C sensors included
1.17 lb
(530 g)
MR4 Series
DIN Rail and Panel Mount Modules
Single-Stage Electronic Temperature Controls
Code No. LIT-1900003
Repair Information
If the MR Series Defrost Control Modules fails to
operate within its specifications, replace the unit.
For a replacement control, contact the nearest
Johnson
Controls® representative.