Liebert Precision Cooling System DS - Manual (Page 84)

Piping
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8.1.2 Humidifier Supply Water—Optional Infrared
• 1/4" supply line; maximum water pressure is 150 psi (1034kPa)
• Size humidifier supply line for 1 gpm (3.8 l/m), with a minimum water pressure of 20 psi (138kPa)
• Do not supply de-ionized water to the humidifier
8.1.3 Requirements of Systems Using Water or Glycol
These guidelines apply to the field leak checking and fluid requirements for field piping systems, includ-
ing Liebert chilled water, hot water, condenser (water or glycol), GLYCOOL and drycooler circuits.
General Guidelines
• Equipment damage and personal injury can result from improper piping installation, leak check-
ing, fluid chemistry and fluid maintenance.
• Follow local piping codes, safety codes.
• Qualified personnel must install and inspect system piping.
• Contact a local water consultant regarding water quality, corrosion protection and freeze protec-
tion requirements.
• Install manual shutoff valves at the supply and return line to each indoor unit and drycooler to
permit routine service and emergency isolation of the unit.
!
CAUTION
Risk of frozen fluids. Can cause equipment damage and building damage.
Freezing system fluids can rupture piping. Complete system drain-down cannot be ensured.
When the field piping or unit may be exposed to freezing temperatures, charge the system
with the proper percentage of glycol and water for the coldest design ambient.
Automotive antifreeze is unacceptable and must NOT be used in any glycol fluid system.
!
CAUTION
Risk of corrosion. Can cause equipment damage.
Read and follow individual unit installation instructions for precautions regarding fluid
system design, material selection and use of field-provided devices. Liebert systems contain
iron and copper alloys that require appropriate corrosion protection.
Contact a local water consultant regarding water quality, corrosion and freeze protection
requirements.
Water chemistry varies greatly by location, as do the required additives, called inhibitors,
that reduce the corrosive effect of the fluids on the piping systems and components. The
chemistry of the water used must be considered, because water from some sources may
contain corrosive elements that reduce the effectiveness of the inhibited formulation.
Preferably, surface waters that are classified as soft and are low in chloride and sulfate ion
content should be employed. Proper inhibitor maintenance must be performed in order to
prevent corrosion of the system. Consult glycol manufacturer for testing and maintenance of
inhibitors.
Commercial ethylene glycol (Union Carbide Ucartherm, Dow Chemical Dowtherm SR-1 and
Texaco E.G. Heat Transfer Fluid 100), when pure, is generally less corrosive to the common
metals of construction than water itself. It will, however, assume the corrosivity of the water from
which it is prepared and may become increasingly corrosive with use if not properly inhibited.
!
CAUTION
Risk of oxide layer formation. Can cause equipment damage.
Idle fluid allows the collection of sediment that prevents the formation of a protective oxide
layer on the inside of tubes. Keep unit switched ON and system pump operating.