Carrier 16DF013-050 - Manual (Page 45)

Shutdown Below Freezing Conditions — Begin
by shutting the machine down with Normal Shutdown
Procedure.
Then transfer most of the refrigerant into the solution:
1. Turn the burner control switch to OFF and depress the
machine Start button. Then depress the machine Stop but-
ton to start the dilution cycle.
2. Open the changeover valve ‘‘B’’ under the refrigerant tank
to drain refrigerant into the absorber.
3. After about 10 minutes, close the changeover valve ‘‘B’’.
4. The machine will stop after a dilution period of about
15 minutes.
The refrigerant circuit requires special treatment to prevent
freezing:
1. Fill a hose with water (to avoid letting air into the ma-
chine) and connect the hose between the solution pump
and refrigerant pump service valves.
2. Push machine Start button (while burner control switch
is still in the OFF position) to start the pumps.
3. Open both pump service valves for about 15 minutes. The
solution pump discharge pressure is higher so solution
will flow into the refrigerant circuit to provide antifreeze
protection.
4. Depress machine Stop button, return the burner control
switch to ON, open the control panel main circuit breaker
(MCB), and remove the transfer hose.
Completely drain all water tube bundles and flush all tubes
with an antifreeze chemical such as glycol.
Actions After Abnormal Shutdown (Fig. 26 ) —
Abnormal stop occurs automatically when any of the safety
devices sense a condition exceeding their normal safe op-
erating limit. When this happens, the fuel valve is closed,
the alarm buzzer sounds, and the machine shuts down. The
cause of the safety shutdown will be displayed in code by
the status indicator on the front of the control panel. These
codes are listed in Table 16. In case of a burner or combus-
tion failure, an alarm light on the burner control panel also
illuminates.
Some safety conditions will close the fuel valve imme-
diately, and others will first modulate the burner to the mini-
mum firing position for a normal low fire shutdown. Also,
most safety conditions will allow the normal shutdown di-
lution period but some will stop the machine immediately
without dilution. The latter conditions should be corrected
as quickly as possible to allow a restart or manual dilution
before solution crystallization can occur. See Abnormal Shut-
down in the Machine Controls section, page 29 for limit set-
tings and shutdown action for each safety type.
Take the following actions after an abnormal shutdown:
1. Identify the problem from the control panel status indi-
cator, and also from the burner control panel if it is a burner
problem.
2. Depress the machine Stop button to silence the buzzer
and to reset the control circuit for a restart after noting
the failure code.
3. Correct the cause of the problem and restart the machine
to be sure it operates normally. See Troubleshooting Guide,
pages 54 - 56 for remedies. If shutdown occurred with-
out adequate dilution, this should be done as soon as
possible.
Table 16 — Safety Devices Status
Indication Summary
INDICATION CAUSE SAFETY DEVICE
E01 Chilled water
low temperature Chilled water
low temperature cutout
E02 Chilled/hot water
low flow Flow switch
Chilled/hot water pump
interlock
E03 Cooling water
low flow Optional Flow Switch
Cooling water pump
interlock
E04 Hermetic pumps
overload Solution pump thermal
relay
Solution pump coil
thermostat
Refrigerant pump thermal
relay
E05 Generator high
temperature or
high pressure High temperature
generator
pressure switch
High temperature
generator solution
temperature sensor
E06 Exhaust gas
high temperature Exhaust gas high
temperature thermostat
Fire tube high
temperature thermostat
E07 Absorber high
temperature Absorber solution
temperature sensor
E08 Burner — no ignition Burner flame detector
and combustion controller
E09 Burner — misfire Burner flame detector and
combustion controller
E10 External limit device External emergency
stop switch
Main power failure
E12 Chilled/hot water
flow check Flow switch,
pump interlock
E13 High-temperature
generator,
solution high level High-temperature
generator solution
level sensor
E17 Leaving chilled/hot
water temperature Chilled/hot water
outlet temperature
sensor
E18 Absorber solution
temperature Absorber solution
temperature sensor
E19 High-evaporator
generator,
refrigerant temperature High-temperature
generator, refrigerant
temperature sensor
E20 Entering chilled/
hot water
temperature Chilled/hot water inlet
temperature sensor
E24 High-temperature
generator,
solution temperature High-temperature
generator, solution
temperature sensor
E90 Insufficient dilution Control circuit
power failure
Actions After Power Interruption — If the control
power is interrupted during operation, the chiller stops im-
mediately without the normal shutdown sequence and
dilution.
Solution crystallization can occur if the concentration is
high (chiller was operating with a relatively large load). If
so, depress the Start button to restart the machine as soon as
possible after the power is restored. The machine will not
restart automatically when power is recovered. If the chiller
cannot be operated because of crystallization, follow the So-
lution Decrystallization instructions in the Maintenance Pro-
cedures section, page 53.
45