JOHNSON CONTROLS
169
SECTION 8 – SERVICE
FORM 100.50-NOM12
ISSUE DATE: 04/02/2019
8
MIN VOLTS
DC
MAX VOLTS
DC
MODULATING
FURNACE 1A
STATUS
FURNACE 1A
HIGH
STATUS
FURNACE 2
STATUS
FURNACE 3
STATUS
FURNACE 1B
STATUS
3.390
3.706
OFF
OFF
OFF
ON
ON
3.528
3.854
ON
OFF
OFF
ON
ON
3.665
4.001
OFF
ON
OFF
ON
ON
3.803
4.149
ON
ON
OFF
ON
ON
3.941
4.296
OFF
OFF
ON
ON
ON
4.078
4.444
ON
OFF
ON
ON
ON
4.216
4.592
OFF
ON
ON
ON
ON
4.354
4.739
ON
ON
ON
ON
ON
TABLE 63 -
FURNACE STATUS INPUT STAGED GAS HEAT
MIN VOLTS DC
MAX VOLTS DC
FURNACE 1 STATUS FURNACE 2 STATUS FURNACE 3 STATUS
0.086
0.166
OFF
OFF
OFF
0.224
0.313
ON
OFF
OFF
0.361
0.461
OFF
ON
OFF
0.499
0.609
ON
ON
OFF
0.637
0.756
OFF
OFF
ON
0.774
0.904
ON
OFF
ON
0.912
1.051
OFF
ON
ON
1.050
1.199
ON
ON
ON
TABLE 62 -
FURNACE STATUS INPUT MODULATING GAS HEAT (CONT'D)
FAULTS
A fault is defined as an abnormal condition, which
results in the shutdown of an operating system or the
complete unit. The presence of a fault condition indi-
cates a situation in which possible damage to the unit
may occur if the unit or system were allowed to con-
tinue to operate. There are four types of faults.
• Unit Lockout – The complete unit is shutdown
and locked out. A manual reset is required to re-
start the unit after the fault has been corrected.
• System Lockout – One of the compressor systems
or other component is shutdown and locked out. A
manual reset is required to restart the system after
the fault has been corrected.
• Unit Auto Reset – The complete unit is shutdown
but the unit will restart automatically when the
fault condition is cleared.
• System Auto Reset – One of the compressor sys-
tems or other component is shut down but the sys-
tem or component will restart automatically when
the fault condition is cleared.
A UNIT LOCKOUT can be reset by turning the “
LO-
CAL STOP”
switch OFF for 5 seconds and then back
ON. If the cause of the lockout has been corrected the
unit will reset and begin proper operation.
A SYSTEM LOCKOUT except for COMPR # LOCK-
OUT and COMPR # LPCO SAFETY LOCKOUT can
be reset by turning the “LOCAL STOP” switch OFF
for 5 seconds and then back ON. A COMPR # LOCK-
OUT and COMPR # LPCO SAFETY LOCKOUT
must be reset by entering the OPTIONS key and the
COMPRESSOR SYSTEMS # subsection, which has
the lockout. Then use the up and down arrow key to
go to COMP SYS # STATUS. The current status is
LOCKOUT. Press the check key (√) and use the right
arrow key to change LOCKOUT to RUN.
In addition to faults the User Interface will also dis-
play warnings. A warning is defined as an abnormal
condition under which the unit continues to operate.
Warnings will not require the unit to shut down; how-
ever, they may require the IPU board to disable certain
functions that may result in the unit operating less ef-
ficiently or eliminate certain features.
