107
This alarm will disable mechanical cooling and will require a
manual reset. This alarm may be disabled once the reverse ro-
tation check has been verified by setting
Configuration
COOL
REV.R
= Yes.
A150 (Unit is in Emergency Stop)
If the fire safety input condition occurs to indicate a fire or
smoke condition, then Alarm code 150 will occur and the unit
will be immediately stopped. Through separate inputs the unit
can be put into purge, evacuation, and pressurization. This re-
quires a manual reset.
If the CCN point name “EMSTOP” in the System table is set to
emergency stop, the unit will shut down immediately and
broadcast an alarm back to the CCN indicating that the unit is
down. This alarm will clear when the variable is set back to
“enable.”
A151 (Illegal Configuration - More Than Two Elec. Heat
Stages)
The unit cannot be configured with more than two electric heat
stages. An alarm code will occur when the unit is wrongly
configured.
T153 (Real Time Clock Hardware Failure)
A problem has been detected with the real timeclock on the
MBB. Try resetting the power and check the indicator lights. If
the alert continues, the board should be replaced.
A154 (Serial EEPROM Hardware Failure)
A problem has been detected with the EEPROM on the MBB.
Try resetting the power and check the indicator lights. If the
alarm continues, the board should be replaced.
T155 (Serial EEPROM Storage Failure Error)
A problem has been detected with the EEPROM storage on the
MBB. Try resetting the power and check the indicator lights. If
the alert continues, the board should be replaced.
A156 (Critical Serial EEPROM Storage Failure Error)
A problem has been detected with the EEPROM storage on the
MBB. Try resetting the power and check the indicator lights. If
the alarm continues, the board should be replaced.
A157 (A/D Hardware Failure)
A problem has been detected with A/D conversion on the
boards. Try resetting the power and check the indicator lights.
If the alarm continues, the board should be replaced.
A168 (Low Ambient Control Board (SCB2) Comm Failure)
This alarm indicates that there are communications problems
with the Low Ambient Option SCB2 board. Cooling on the
unit is disabled until communication with the SCB2 control
board is re-established. The alarm will automatically reset.
Reason for failure may be due to incorrect wiring, power loss
to the control board, or damage to the RS-485 drivers on the
LEN bus.
A169 (Expansion Valve Control Board Comm Failure)
Cooling is disabled until communication with the EXV control
board is re-established. Recovery is automatic. Reason for fail-
ure may be due to incorrect wiring, power loss to the control.
A171 (Staged Gas Control Board Comm Failure)
This alarm indicates that there are communications problems
with the staged gas heat control board, which is located in the
gas section on units equipped with staged gas heat. If this
alarm occurs, the staged gas heat will be disabled. The alarm
will automatically reset.
A172 (Controls Expansion Module Comm Failure)
This alarm indicates that there are communications problems
with the controls expansion board. All functions performed by
the CEM will stop, which can include demand limit, reset, fire
control modes, and the fan status switch. The alarm will auto-
matically reset.
A173 (ECB1 Board Communication Failure)
This alarm indicates that there are communications problems with
the economizer control board. This will result in the economizer
and the power exhaust not working and the dampers to be fully
closed. The exhaust fans will stop. The alarm will automatically
reset.
A174 (ECB2 Board Communication Failure)
This alarm indicates that there are communications problems
with the ECB2 which controls the VAV unit indoor fan inverter
speed and hot gas bypass on CV and VAV units. Because the
control of the fan is critical to unit operation, the unit will be
stopped. The alarm will automatically reset.
T177 (4-20 mA Demand Limit Failure)
This alert indicates a problem with the optional remote 4 to 20 mA
demand limit signal (
Inputs
4-20
DLM.M
) that is connected
to the CEM module (if the signal reads less than 2 mA). If this oc-
curs, then demand limiting will be disabled. The unit must be con-
figured for 4 to 20 mA Demand Limiting using the Demand Limit
Select (
Configuration
DMD.L
DM.L.S
).
T178 (4-20 mA Static Pressure Reset/VFD Failure)
If this transducer fails (if the signal reads less than 2 mA on the
input of the CEM module), and the unit is configured to per-
form static pressure reset or remote control of the supply fan
VFD with this transducer, no static pressure reset or VFD con-
trol will be performed and an alert will be generated. Recovery
is automatic. Reason for error is either a faulty sensor, wiring
error, or damaged input on the CEM control board.
A179 Circuit A ODF VFD Failure
The MBB has received a fault status from the outdoor fan
VFD(s). The A circuit of the 60 ton MCHX or the unit will not
be allowed to operate, and a manual reset is required. The VFD
keypad will indicate which fault has occurred.
A180 Circuit B ODF VFD Failure
The MBB has received a fault status from the outdoor fan
VFD(s). The B circuit of the 60 ton MCHX or the unit will not
be allowed to operate, and a manual reset is required. The VFD
keypad will indicate which fault has occurred.
A181 Circuit A ODF VFD Communication Failure
This alarm indicates that there are communication problems
with the Circuit B OD fan VFD. The cooling function on the B
circuit or the unit is disabled until communication with the OD
fan VFD(s) is re-established.
A182 Circuit B ODF VFD Communication Failure
This alarm indicates that there are communication problems
with the Circuit B OD fan VFD. The cooling function on the B
circuit or the unit is disabled until communication with the OD
fan VFD(s) is re-established.
T183 (Compressor Lockout Low Ambient)
When the outdoor ambient temperature (OAT) is below the com-
pressor lockout temperature setting (OATLCOMP), an alert will
occur to indicate the setting situation. If the unit is equipped with
Low Ambient or GreenSpeed option, the OATLCOMP setting can
be lower than the default 40°F to the minimum of –20°F.
A200 (Linkage Timeout Error — Comm Failure)
If linkage is established via the CCN with ComfortID™ termi-
nals, a 5-minute timeout on loss of communication will be
monitored. If 5 minutes expires since the last communication
from a VAV Linkage Master, the unit will remove the link and
flag the alert. When the rooftop loses its link, the temperature
and setpoints are derived locally. Recovery is automatic on re-
establishment of communications. Reason for failure may be
wiring error, too much bus activity, or damaged 485 drivers.
Summary of Contents for WEATHERMAKER 48A2020
Page 112: ...112 Fig 20 Typical Main Control Box Wiring Schematic 48 50A Units ...
Page 113: ...113 Fig 21 Typical Auxiliary Control Box Wiring Schematic ...
Page 114: ...114 Fig 22 Typical 2 Stage Gas Heat Wiring Schematic Size 060 Units Shown ...
Page 115: ...115 Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown TO NEXT PAGE ...
Page 116: ...116 Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown cont ...
Page 117: ...117 Fig 24 Typical Electric Heat Control Schematic 50 Series Size 060 Units Shown ...
Page 118: ...118 Fig 25 Typical Controls Option Wiring Schematic SW1 SW2 OR DEHUMIDIFY SWITCH ...
Page 119: ...119 Fig 26 Typical Power Schematic 48 50A2 A3 A4 A5 060 Unit Shown ...
Page 120: ...120 Fig 27 Typical Power Schematic of Greenspeed Low Ambient Option 48 50A 060 Unit Shown ...
Page 121: ...121 Fig 28 Typical Small Chassis Component Location Size 020 035 Units ...
Page 122: ...122 Fig 29 Typical Large Chassis Component Locations Size 040 060 Units ...
Page 185: ...185 APPENDIX C VFD INFORMATION cont Fig F Internal Enclosure Fan Replacement A48 7716 ...