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Operating Procedures
Electrical Code, a disconnect must be installed within the
line of sight of the electrical and control panel. Should an
emergency condition arise, the disconnect must be opened
to shut down all voltage to the chiller.
There are several ways to interrupt power to all or part of
the chiller:
•
Disconnect the primary power source from the building
that feeds electricity to the chiller. This occurs in
sudden emergencies (usually weather-related) or
planned maintenance shut-downs.
•
Press the panel disconnect switch on the exterior door
of the chiller's main power distribution panel, if so
equipped.
•
Move the circuit breaker switch to the OFF position
(CB-1 and CB-2) on the power distribution panel. This
cuts power to all of the chiller modules.
•
Move the circuit breaker switch to the OFF position
(CB-1 and CB-2) on a module's electrical and control
panel. This cuts power to the compressors in a single
module. It does not cut power to electrical and control
panel or other chiller modules.
•
Press the SYSTEM ON button on the touchscreen
interface panel that is built into the power distribution
panel door.
Note: Pressing the ON-OFF button on the touchscreen
interface panel does not de-energize the chiller or
the high voltage current into each module's electrical
and control panel. This action sends a command to
the controller in each module's compressors to
discontinue electrical current to that component.
Water Quality Guidelines
The chiller is equipped with high efficiency compact
brazed-plate heat exchangers (BPHE). Water quality must
be maintained periodically by the end user to avoid scaling
and corrosion inside the heat exchangers.
Table 10. Water quality guidelines
Element/Compound/Property
pH
Conductivity
Total Hardness
Free Chlorine
Ammonia (NH
)
3
Table 11. Glycol performance impact factors
Range Factor
Propylene Glycol Concentration
Lowest Ambient Temperature
Recommended Minimum
Leaving Fluid Temperature
46
Value/Unit
7.5 - 9.0
<500 μS/cm
4.5 - 8.5 dH°
<1.0 ppm
<0.5 ppm
Glycol Concentration Percentages and Performance Impact
30%
10°F (-12 °C)
25°F (-4 °C)
Table 10. Water quality guidelines (continued)
Element/Compound/Property
2–
Sulphate (SO
)
4
Hydrogen Carbonate (HCO
3–
2–
(HCO
)/(SO
)
3–
4
(Ca + Mg)/(HCO
)
3–
Chloride (Cl-)
Notes:
1.
Total Hardness/corrosion: Water with high hardness can cause
corrosion problems due to its high ion content (Ca+2, Mg+2, Fe+2)
which also means a high electrical conductivity and a high total
dissolved solid (TDS). For this reason, too high hardness values
should be avoided, not only due to higher risk of scaling, but also for
corrosion risk. On the other hand, soft water, but not necessarily
cation exchange softened water, may in contrast have a low buffering
capacity and so be more corrosive. If the hardness values are
outside the recommended range, other parameters such as oxygen
content, conductivity, and pH values should be considered to
evaluate the corrosion risk.
2.
Fe3+ and Mn4+ are strong oxidants and may increase the risk for
localized corrosion on stainless steels in combination with brazing
material copper.
Monitor Water Quality
Maintaining water/glycol mixture quality and cleanliness is
critical to chiller health and maintainability. Strainers should
be checked and cleaned on a regular basis. Water/glycol
mixture samples should be taken and tested by a
professional lab. The results will enable the accurate
adjustment of quality thereby increasing the operational life
of the chiller.
Note: Trane will not validate the chiller warranty if the
proper water/glycol mixture composition and quality
is not maintained.
Maintain Glycol Level
The temperature of the refrigerant in a brazed-plate
evaporator is not uniform throughout the heat exchanger.
The refrigerant temperature is approximately 6°F to 12°F
colder than the corresponding fluid temperature depending
on many factors such as the heat exchanger design, glycol
percentage, operating fluid temperatures, refrigerant,
system flow rate, etc. When the chiller has a set point that
is within 12°F (6.7°C) of the freezing point of the water/
glycol in use, take precautions against freezing.
See
Table 11, p. 46
below for the recommended glycol
concentrations and performance impact.
40%
-4°F (-20°C)
10°F (-12°C)
Value/Unit
<100 ppm
60 – 200 ppm
>1.5
>0.5
<200 ppm
50%
-20°F (-29°C)
-10°F (-23°C)
ARTC-SVX008A-EN
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