FANs 125, 121
Temperature Controls Section
A
Installation Bulletin
Issue Date 1199
© 1999 Johnson Controls, Inc.
1
Part No. 24-7664-1687, Rev. A
www.johnsoncontrols.com
Code No. LIT-125193
IMPORTANT:
All MR4 controls are designed for
use only as operating controls.
Where an operating control
failure would result in personal
injury or loss of property, it is the
responsibility of the installer to
add devices (safety, limit
controls) or systems (alarm,
supervisory systems) that protect
against, or warn of, control
failure.
Refer to the
MR Series Refrigeration Temperature
Controls Product Bulletin, LIT-125199
, for necessary
information on operation and performance
specifications for this product.
M
ounting
The MR4 control is not position-sensitive but should be
mounted for convenient wiring and adjustment.
To mount the Panel Mount version, ensure that there
is at least 2 3/4 inches (70 mm) space behind the
panel. Make a cutout 1 3/16 x 2 13/16 inches
(29 x 71 mm). Remove retaining clip from the control.
Insert the control into the hole. Install retaining clip and
adjust for tightness.
To mount the DIN Rail Mount version, install the DIN
rail where appropriate. Snap the control onto the rail
into position.
R
epair and Replacement
Field repair of the control should not be made. In case
of a defective or improperly functioning control, check
with your nearest authorized Johnson Controls/PENN
distributor. When contacting the supplier for
replacement, state the model number of the control.
This number can be found on the data plate.
W
iring
!
WARNING:
Shock Hazard.
To avoid
possible electrical shock or
damage to equipment,
disconnect power supply before
wiring any connections.
Follow these wiring guidelines:
All wiring must conform to the National Electric
Code and local regulations.
Make all wiring connections using adequate gauge
copper conductors only. Connectors are rated for
14-22 AWG wiring.
Internal to Control
V1 V2
Power
Supply
Compressor Evaporator
Fan
Defrost
SC
S2
S1
D CD
Process Temperature Sensor
Binary Input
Alarm
Evaporator
Temperature
Sensor
Fr
Fn
Df
A1 A2
C1
C2
C3
Sensor
Common
Binary Common
Terminal
Not Used
Refer to Rating Table for more information.
Figure 1: MR4 DIN Rail Mount Control
C
SC
S1
S2
D
V1 V2
Internal to Control
Power
Supply
Evaporator Temperature
Sensor
Binary
Input
Process Temperature Sensor
Common
Compressor
Alarm
Defrost
Evaporator
Fan
Fr
A1 Df
Fn
Refer to Rating Table for more information.
Figure 2: MR4 Panel Mount Control
I
NSTALLATION
B
ULLETIN
MR4 Refrigeration Temperature/Defrost Control
