Carrier 19DG - Manual

Carrier initiai Start-Up Instructions
/
Heritìetic Cpfìtrifugal Liguid Chillers
INTRODUCTION
All persons involved in start-up and operation
of the 19DG Machine should understand these
instructions and all applicable Job Data before
initial start-up. The instructions are arranged in the
proper sequence for machine start-up.
Job Data Required
1. Machine assembly, wiring and piping prints.
2. Starter details
3. 19DG Installation Instructions
4. 19DG Operating and Maintenance Ins
Equipment Required
1. Mechanic’s tools
Volt-ohmmeter and clamp 2
.
3.
4.
5.
6
.
7.
Manometer, absolute pressu'
Leak detector, halide or el№tf^ic
Refrigerant drum charging valve (F
5/8-in. SAE
X
3/4-in. MPT ada rter
Five to ten ft of copper tub!
to fit 5/8-in. SAE connection;
)
2/o7
plastic hose
INITIAL PREPIAR
CAUTION; Do not síai^iítempressor or oil
pump, even for a rotation check, unless
compressor has been charged with oil and
machine charged with refrigerant.
Machine Tightness — A shipping vacuum was
applied to the refrigerant side of the 19DG
Machine before shipment from the factory. Over a
period of time, during shipment or storage, part of
this vacuum may be lost. The loss of a small
amount of vacuum may be acceptable and within
Carrier’s machine tightness standards. To deter­
mine if the vacuum loss is acceptable;
1. Record and date vacuum reading shown on the
compressor-mounted oil reservoir gage (Eig. 1).
2. Determine vacuum leak rate by comparing this
reading with reading taken when machine was
received. Use the formula:
^ , vacuum difference
Leak rate == ------------------------------------ -
no. of days between readings
3. If leak rate is 0.05 in. Hg or less per 24 hours,
machine is sufficiently tight. If leak rate
exceeds 0.05 in. Hg per 24 hours, perform
Refrigerant Pressure Test and correct leakage.
EXCESSIVE OR TOTAL VACUUM LOSS can be
caused by accidental opening of a valve or other
connection. If this is suspected, proceed as follows;
1. Install a mercury manometer (absolute pressure
type) at the cooler charging valve (Eig. 1). A
annot indicate the small amot
;eptable during a short p^ridd of
dial gage
leakage act
time.\
Pull a\yaci|ium on the machin'd"equal to 25-in.
■in. bar. (2.^pS'ia). Use an external
mp or enprgize the purge pump (Pig.
jratira^Aio. 2 described on the purge
mrfplate (Pig. 1).
e stand with this vacuum for 24
more. Then perform leak rate test
outlined.
the leak rate is 0.05 in. Hg or less per 24
hours, the machine is sufficiently tight. Perform
Machine Dehydration.
If the leak rate exceeds 0.05 in. Hg per 24
hours, perform Refrigerant Pressure Test and
correct leakage. Perform all steps under
Machine Dehydration.
Remove the mercury manometer from cooler
charging valve.
REFRIGERANT PRESSURE TEST
Pull a vacuum equal to 5 in. Hg ref 30-in. bar.
(12.5 psia) using machine purge pump, and
following operation no. 2 described on the
purge valve operation plate (Fig. 1). An
external vacuum pump connected to the cooler
charging valve may be used, if desired.
2. Charge approximately one gallon of Refrigerant
11 thru the cooler charging valve. Refer to
Charging Refrigerant for procedure.
3. Increase pressure to 8 to 10 psig with dry air or
nitrogen thru the cooler charging valve. Do not
exceed 10 psig.
4. Test all joints, valves, fittings, etc., with a halide
or electronic leak detector.
5. Repair any leaks found. Retest to ensure repair.
MACHINE DEHYDRATION — The refrigerant
side of the 19DG Machine is dehydrated at the
factory. It is usually not necessary to repeat
dehydration at initial start-up. However, if the
machine has been open for a considerable length of
time due to compressor removal, or if there has
been excessive loss of shipping vacuum, it is
recommended that dehydration he repeated.
Dehydration is readily accomplished at normal
room temperature. If room temperature is high,
dehydration takes place more quickly. At low
room temperature, dehydration is extremely diffi­
cult and special techniques must be applied.
Contact your Carrier representative.
Do not start compressor or oil pump even for a
rotation check while machine is und.er dehy­
dration vacuum.
7^
© Carrier Corporation 1971 Form 19DG-3SS