Vertiv Liebert HPC-M Serie Manuel De Service page 17

Maintenance programme --- Monthly check
FANS
CONDENSER AND AIR FILTER
CONTROL
ELECTRICAL CIRCUIT
REFRIGERATION CIRCUIT
CHILLED WATER CIRCUIT
8 --- Options and Accessories
8.1 --- Pump Group
The centrifugal pump units are direct driven, with close----
coupled motors and a single shaft; the induction motor has
2 or 4 poles with IP 54 protection and class F insulation.
The materials used for the pump main components are:
• Pump body in cast iron
• Impeller in brass or cast iron according to the models
• AISI 303 or AISI 430 stainless steel shaft, depending
on the models
• Mechanical seal X7X72Z7 in ethylene---propylene, ce-
ramic and impregnated graphite, suitable for the use
of mixtures containing ethylene glycol.
Check that the fan rotates freely without any abnormal noise, and ensure that the bearing is not
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running hot.
Also check the current absorption.
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Check the conditions of the filters (if they are supplied); if necessary clean them (including the
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electric board ventilation filter).
Check the condenser coils, cleaning if necessary with compressed air or soft brushes.
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Check that the control equipment, LEDs and display are operating correctly.
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Check the supply voltage.
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Check the operation of the cover heaters.
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Check the operation of the solenoid valves.
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Check the conditions of the remote control switch contacts.
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Check the operation of the evaporator resistance.
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Check the electrical supply on all phases.
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Ensure that all electrical connections are tight.
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Check the condensing and the evaporating pressures (to be done by a refrigeration technician).
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Check the compressor's current absorption, the delivery temperature and possible unusual
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noises.
Check the freon charge by means of the sight glass.
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Check that the safety devices operate correctly.
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Check the correct operation of the thermostatic valve (superheat between 5 ---8
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Check that the oil level indicated by the compressor sight glass is higher than the min. value.
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Ensure that there are no water leaks.
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Bleed any air out of the hydraulic circuit using the bleed valve on the chilled water coil.
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Verify the correct water flow inlet.
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Check the inlet --- outlet liquid temperature and pressure.
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Check the correct operation of the three---way valve (if installed)
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Check if the system is charged with the specified glycol percentage and that no ice has formed in
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the hydraulic circuit.
Check the evaporator cleanliness.
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English
The pump units have been chosen and sized to operate
within specific limits, namely:
• water / ethylene glycol mixtures up to 65 / 35% in
weight
• temperatures of the standard pumped fluid not lower
than 4°C.
The hydraulic circuit includes, for each pump, a suction
shut---off valve and a discharge check valve.
Inthe electricalpanelthereare automaticmagneto---ther-
mal protections for each pump; the microprocessor con-
trol manages the operating rotation between the two
o
C).
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