Johnson Controls Penn MR4 Installation Bulletin

MR4 Refrigeration Temperature/Defrost Control
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.
© 1999 Johnson Controls, Inc.
Part No. 24-7664-1687, Rev. A
Code No. LIT-125193
I B
NSTALLATION ULLETIN
W
iring
!
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.
Common
Temperature Controls Section A
WARNING: Shock Hazard. To avoid
possible electrical shock or
damage to equipment,
disconnect power supply before
wiring any connections.
Process Temperature Sensor
Sensor
Binary Input
Common
Evaporator
Temperature
Sensor
S1 SC D CD S2
Internal to Control
Not Used
Terminal
V1 V2 C1 Fr
C3
Power Compressor Evaporator
Supply
Refer to Rating Table for more information.
Figure 1: MR4 DIN Rail Mount Control
Refer to Rating Table for more information.
C Fr A1 Df Fn V1 V2
Power
Defrost
Supply
Alarm
Evaporator
Compressor
Fan
Process Temperature Sensor
Figure 2: MR4 Panel Mount Control
FANs 125, 121
Installation Bulletin
Issue Date 1199
Binary Common
Alarm
A1 A2
Fn C2 Df
Defrost
Fan
Internal to Control
D S1 SC S2
Binary
Input
Evaporator Temperature
Sensor
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