FläktGroup Multi-DENCO, Руководство по эксплуатации

Страница: 89 / 120

Multi -DENCO Commissioning
FläktGroup DC-2013-0101-GB • Subject to modifications • R4-05/2018 89
The table refers to general percentage concentration of Ethylene Glycol. Always con-
tact the manufacturer for specific values for their variant of Glycol:
Ethylene glycol gives added protection against system damage from bursting:
– On freezing water expands about 9%
– This volume change may rupture piping and cause catastrophic system failure
– Adding ethylene glycol significantly reduces the expansion the solution upon free-
zing, thus reducing the likelihood of system pipes bursting
– The higher the ethylene glycol concentration, the less the expansion
– Pure ethylene glycol does not expand at all upon freezing
Refer to the Tab. 8-3 for freeze and burst protection. In a system not operational in win-
ter, it may be sufficient to choose a lower fluid concentration, one that merely protects
against bursting, since some crystal formation in the fluid will not be harmful.
8.3.7 Water balancing
3 & 2-port Drive Open Drive Close Valves (DODC)
•
Ensure the valve is '100% open' during water balancing; failure to follow this may
result limited capacity of the unit
•
To force the valve to be 100% open, use the controls to modify the set-point
temperature (supply or return) so that it is below the water temperatures within the
chilled water circuit
2-port Pressure Independent Control Valves (PICV)
Temperature Percentage concentration needed for (%):
°C Freeze Protection Burst Protection
-7 16
11
-12
25
16
-18 32
21
-23
39
26
-28
44
31
-34 48
36
-40
52
37
-46 55
38
Tab. 8-3
NOTE!
The following instructions are for 2-port PICV valves used with C5-12 controllers in
Multi -DENCO units. For all other configurations or equipment please see separate
manuals or contact your local office.