User's Manual
Water quality and leveling requirements, and condensation management 66
Closed-loop water specifications Raw water Treated water system
Molybdenum (Mo) 50–300 ppm 50–300 ppm
Tolytriazole 15–20 ppm 15–20 ppm
Suspended solid < 1 µm < 1 µm
Monitoring the quality of cooling solutions
Depending on the type of installation, it is advisable to put in place certain processes and procedures for
monitoring the quality of the cooling solution and for performing preventative maintenance. The following
table lists common types of contamination and techniques to eliminate them:
Type of impurity Procedure
Mechanical
contamination
Filter the water using 1-micron filter (3.9e-5 in), sieving
filter, sand filter, cartridge filter, or pre-coated filter.
Hardness too high Soften the water through ion exchange.
Moderate content of
mechanical impurities
and hardness agents
Add stabilizers, dispersing agents, or both to the water.
Use Azole treatment for copper corrosion.
Moderate content of
chemical impurities
Use Anodic inhibitors: Nitrite based treatment
Use Cathodic inhibitors: Molybdate based treatment
Inoculate the water with passivators, inhibitors, or both.
Biological impurities,
microbacteria, and
algae
Inoculate the water with biocides.
To ensure ongoing safe reliable operation of the closed-loop cooling system, see "Acceptable water
quality range (on page 64)."
Frost damage
To avoid frost damage, the water temperature must not be allowed to fall below the minimum permissible
temperature of +4 ºC (+39.2 ºF) at any point in the water cycle.
Before storage or transportation at sub-zero temperatures, the water cycle must be drained completely
using compressed air. Avoid setting the target temperature lower than is necessary because the danger of
falling below the dew point increases as water temperature decreases (condensation buildup). Ensure that
the enclosure is sealed on all sides, and in particular at the cable inlet (condensation formation).
Leveling requirements
Adjust the MCS leveling feet so that the unit is level.
For more information about seismic area considerations, refer to the HP Modular Cooling System Site
Preparation Guide on the HP website (http://www.hp.com
).