York YHAU-CW Manual page 140

SECTION 7 – MAINTENANCE
TABLE 28 - MAINTENANCE AND INSPECTION (CONT'D)
TASK
Measurement of
insulation resistance of
electric devices
Check of terminals for
looseness
Check of operation of
control panel
Check capacity of purge
unit
Check of leakage through
purge solenoid valves
Overhaul check of purge
solenoid valves
Check of airtightness
Check continuity of
protective bonding circuit
Analysis of quality of
chilled water, cooling
water, and steam drain
Check of quantity of
solution and refrigerant
Disassembly inspection
and cleaning of solution
pump and refrigerant
pump
Disassembly inspection
and cleaning of vacuum
pump
Replacement of gaskets
of airtight parts
Inspection of chilled
water box and
replacement of packing
Inspection of cooling
waterbox and
replacement of gasket
Inspection of the steam
box and replacement of
gasket
C = Customer, S = Johnson Controls Service
140
CONTENTS
Measure the insulation resistance of the main circuit and motors
(solution pump, refrigerant pump) mainly to check for lowering
of insulation. When measuring the insulation resistance, be sure
to disconnect the wires of the temperature controller, and other
related controls.
Check each terminal in the control panel for looseness.
Check the operation of the control panel to prevent troubles
caused by malfunction of the control panel.
See Purge Procedure on page 132. Check the capacity of the
purge unit.
By measuring vacuum down speed, check for leakage through
purge solenoid valves.
Perform overhaul of purge solenoid valves.
Measure the quantity of non-condensable gas discharged from
the vacuum pump.
Check continuity of protective bonding circuit.
Reliable water treatment companies are available in most
larger cities to supply a water treating process which will greatly
reduce the corrosive and scale forming properties of almost any
type of water. Be sure to request the first analysis within one
month after the test operation is started.
The solution is not consumed, but the refrigerant is discharged
little by little each time purging is performed. If the quantity
of the refrigerant becomes insufficient, the condensation
preventive function does not work normally. Accordingly, check
the quantity of the refrigerant.
Sleeve bearings are used for the solution pump and refrigerant
pump, and they are normally lubricated with water solution of
lithium bromide and refrigerant. Since excessive wear can
cause a pump problem, disassemble and inspect the bearings.
The internal strainer must also be cleaned.
Disassemble, inspect, and clean the vacuum pump to maintain
its capacity.
Replace the gaskets of the airtight parts to maintain the
airtightness of the absorption chiller.
Open the waterbox cover, check the inside paint for damage,
and check the inside of the tubes for scales.
• Open the steam box.
• Check the tube plate and the expanded sections of the tubes
for abnormal thinning.
FORM 155.31-ICOM2.EN.UL
ISSUE DATE: 12/21/2018
FREQUENCY SCOPE
S
Yearly
S
S
Monthly S
S
Yearly
S
Every 2-3 months S
Yearly S
Every 2-3 months C
Yearly
(during operation S
at 100%)
2-3 years or
S
10,000 hrs
4 years S
4 years S
Every 2 years S
Every 1 year S
Every 3 years S
JOHNSON CONTROLS