Carrier 16JA - Manual

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Carrier
Hermetic Absorption Liquid Chillers
M A C H I N E O P E R A T I O N
MACHINE START-STOP SYSTEMS
General - The exact start-stop system for a given
machine is established by the customer. Systems
can vary from one installation to another. These
systems and procedures are meant for general
guidelines only.
The three most common types of systems are
given below. Review these systems and decide
which applies to your machine. Then follow the
start-stop procedure given.
NOTE: If machine has been shut down for more
than 2 days, follow procedures under Start-Up
After Limited Shutdown or Start-Up After
Extended Shutdown. In all cases below, when
machine starts, the white run light will en­
ergize. When the machine stops, the light will
go out after automatic dilution.
Automatic Start-Stop System - Starting and stop­
ping with this system is accomplished by an
automatic controller such as a thermostat or
time clock, etc. Also, an AUTO-MANUAL switch
is provided so the machine can be started by-
pressing machine START button with switch in
MANUAL position. All auxiliary equipment is
tied in with the machine control circuit and will
start when the machine starts. If automatic time
delay relays are provided, the machine will start
after a preselected time interval.
The operating engineer must make periodic
checks to ensure that the machine with auxiliary
equipment is operating satisfactorily.
PROCEDURES
1. Place AUTO-MANUAL switch in the AUTOpo-
sition for the machine to start or stop automat­
ically. The automatic controller determines
when the machine starts or stops.
2. To start fully automatic machines after limited
or extended shutdown place the AUTO-MANUAL
switch in MANUAL and press the START
button. Then follow start-up procedures for
limited or extended shutdown. Only after man­
ual start has been completed should the AUTO­
MANUAL switch be placed in AUTO.
NOTE: When the machine shuts down either
automatically or manually, the refrigerant
and solution pumps will continue to run
until automatic dilution is completed.
Semiautomatic Start-Stop System - All auxiliary
equipment used with this system is tied directly
to the control circuit. It is necessary for the
operating engineer to press the START button
to start the condensing water pump, chilled water
pump, machine pumps, and cooling tower fan
(if used).
PROCEDURES
1. Press STOP button to stop machine.
START button to start machine.
Press
NOTE: On shutdown the machine pumps will
continue to run until automatic dilution
is completed.
Semiautomatic Start-Stop System with Manual
Auxiliaries - All auxiliaries must be started
manually.
PROCEDURES
1. Start chilled water pump.
2. Start condensing water pump.
3. Start cooling tower fan (if used). (This depends
on outside temperature.)
4. Press START button to start machine.
5. To stop machine, press STOP button. Then
stop the following:
a. Cooling tower fan (if used).
b. Condenser water pump.
c. Chilled water pump.
NOTE: The refrigerant and solution
pumps will continue to run until auto­
matic dilution is completed.
MACHINE START-UP PROCEDURES
General - Procedures for start-up differ depend­
ing on how long the machine has been shut down.
There are two start-up procedures: Start-up
after limited shutdown (3 days to 3 weeks), and
start-up after extended shutdown (over 3 weeks).
Start-Up After Limited Shutdown
PROCEDURES
1. Start the machine as outlined for your system
under Machine Start-Stop Systems.
2. Check the leaving chilled water temperature.
If temperature drops to design, then steps 3
and 4 are not necessary. If the temperature
does not drop to design, noncondensables are
probably present in the machine. Proceed
with steps 3 and 4.
3. Determine the amount of noncondensables by
taking an absorber loss reading (the temper­
ature difference between the refrigerant and
solution vapor). To determine absorber loss,
refer to Carrier Standard Service Techniques,
publication SM-16. A machine with absorber
loss of less than 6 F can normally be started
without the machine solution becoming solid­
ified. If absorber loss is greater than 6 F,
auxiliary evacuation is recommended. A ma­
chine fully evacuated will normally have an
absorber loss of 2 F or less. Instructions
for auxiliary evacuation are in Carrier Stand­
ard Service Techniques, publication SM-16.
Carrier Corporation 1968 Printed in U.S.A. 1-68 16JA-1SO