4 A
—MR4 Refrigeration Temperature/Defrost Control Installation Bulletin
A
larm and Fault Codes
Table 4: Error Codes and Status
Error Code (Codes will flash on the display.)
System Status
F1
Open or shorted temperature sensor
Alarm output On. Compressor runs according to
SF
. Cycle power
to reset.
F2
Open or shorted evaporator sensor
Alarm output On. Defrost cycle controlled by
di
and
dd
. Correct
problem to reset.
A1
Binary input open for longer than
id
and
iF
= 1
Compressor output Off. Alarm output On. Correct problem to
reset.
A2
Binary input open for longer than
id
and
iF
= 2
Alarm output On. Correct problem to reset.
A3
Binary input open for longer than
id
and
iF
= 3
Fan output Off. Alarm output On.
AH
and
AL
disabled. Correct
problem to reset.
HI
Temperature has reached or exceeded
(se
AH
)
Alarm output On. Correct problem to reset.
LO
Temperature has reached or fallen below
(setpoint
–
AL
)
Alarm output On. Correct problem to reset.
EE
Program failure
Alarm output On. Other outputs Off. Replace control.
O
rdering Information
Table 5: Specifications
Power Requirements
3.7 VA @ 24 VAC 50/60 Hz, Class 2 (20-30 VAC)
Ambient Conditions
Operating
14 to 140
o
F (-10 to 60
o
C); 0 to 95% RH (non-condensing)
Storage
-22 to 176
o
F (-30 to 80
o
C); 0 to 95% RH (non-condensing)
Accuracy
+1.8 F
(+ 1C
)
Agency Listings
UL Recognized: File E194024, CCN XAPX2
Canadian UL Recognized: File E194024, CCN XAPX8
FCC Compliant per Class A Digital Device, Part 15
Canadian DOC Compliant per Class A, Radio Interference Regulations
Table 6: Ordering Information
Product Code Number
Description
MR4PM24-12C
MR4 Panel Mount Control; 2 A99BB-200C sensors included
MR4DR24-12C
MR4 DIN Rail Mount Control; 2 A99BB-200C sensors included
A99BB-200C
Replacement Sensor, lead length: 6-1/2 ft (2 m)
The performance specifications are nominal and conform to acceptable industry standards. For application at conditions beyond these
specifications, consult Johnson Controls/Penn Refrigeration Application Engineering at (414) 274-5535. Johnson Controls, Inc. shall not be
liable for damages resulting from misapplication or misuse of its products.
Controls Group
507 E. Michigan Street
P.O. Box 423
Printed in U.S.A.
Milwaukee, WI 53201
www.johnsoncontrols.com
