HP Modular Cooling System User Manual download pdf (Page 75)

Maintenance 75

Maintenance

Maintenance and service

For information on maintenance and service, refer to the HP website (http://www.hp.com).

Air and water heat exchanger maintenance

The air and water heat exchanger requires no maintenance. If particulates are present in the cooling

water, a filter must be fitted immediately upstream from the water inlet fittings. Check the functionality of

the condensation drainage system regularly. Regularly perform visual inspections for leaks (annually).

Water quality requirements and specifications

Closed-loop water must not contain any lime scale deposits or loose debris. The water should have a low

level of hardness, particularly a low level of carbon hardness. Filters must be used to remove free floating

particulates and be regularly maintained. Additionally, the water must not be so soft that it attacks the

materials with which it comes into contact. It is necessary to periodically add new fresh water, but also to

remove some enriched water. A #30 mesh filter is recommended for filtering water entering the HP MCS,

and a 1 µm filter is suggested for prolonged performance.

Also consider the required set point for the water temperature. Temperatures near or below 0ºC (32ºF)

mean that the chilled water plant condenser is very close to or below the freezing point of the water. The

chilled water temperature to be supplied to the MCS G2 unit is 5ºC (41ºF). Freezing water can cause a

blockage and damage to the unit. So, an additive, such as glycol, might be necessary to lower the

freezing point. However, the heat transfer potential of the water is lower, so the equipment must be

derated properly.

In a cooling loop, metallic materials in a pipe distribution network are in constant contact with

recirculating liquid and can react with impurities to cause corrosion that can develop into leaks or form

deposits and blockages.

The rate of galvanic corrosion depends on the electrical potential between the two dissimilar metals and

the temperature of the liquid.

A 10 degree increase in water temperature can double the rate of corrosion.

For more information, see the HP Modular Cooling System G2 Site Preparation Guide on the HP website

(http://www.hp.com

Acceptable water quality specifications

The following values are water quality ranges required for continuous quality of performance:

Parameter Range

pH 8.0–10

1 2 ... 70 71 72 73 74 75 76 77 78 79 80 81 82 83

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HP Modular Cooling System User Manual Page 75