FANs 125, 121
Temperature Controls Section
A
Installation Bulletin
Issue Date 1199
© 1999 Johnson Controls, Inc.
1
Part No. 24-7664-1695, Rev. A
Code No. LIT-125194
IMPORTANT:
All MR2 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 MR2 Control is not position-sensitive but should
be mounted for convenient wiring and adjustment.
To mount the Panel Mount version, ensure that there
is a space of at least 2-3/4 in. (70 mm) behind the
panel. Make a cutout 1-3/16 x 2-13/16 in.
(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 in
position.
W
iring
!
WARNING:
Shock Hazard.
To avoid
possible electrical shock or
equipment damage, 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
Alarm
Binary
Input
Process
Temperature
Sensor
C
A1
S1 SC
D
CD
Sensor
Common
Binary
Common
A2
Fr
Terminal Not Used
Refer to Rating Table
for more information.
Figure 1: MR2 DIN Rail Control
Internal to Control
V1 V2
D SC S1
Power
Supply
Binary
Input
Process
Temperature
Sensor
Sensor
Common
A1
Alarm
A2
C
Compressor
Fr
Terminal Not Used
Refer to Rating Table
for more information.
Figure 2: MR2 Panel Mount Control
C
anadian DOC Compliance
This digital apparatus does not exceed the Class A
limits for radio noise emissions from digital apparatus
set out in the Radio Interference Regulations of the
Canadian Department of Communications.
I
NSTALLATION
B
ULLETIN
MR2 Refrigeration Temperature/Defrost Control
