Reznor Q6SP Unit Installation Manual - Manual (Page 26)

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Q6sP charging charts - cooling only
application notes on the use of charging charts
This equipment’s cooling systems contain refrigerant under
high pressure, always use safe practices when servicing
the unit. Always review the factory literature and safety
warnings prior to servicing.
All Q6SP-090/120 units are shipped from the factory with
the proper amount and type of refrigerant. Always inspect
the unit rating label to determine the units information prior
to working on the system. Do not mix different refrigerants
or charge the unit with a refrigerant not listed on the unit
rating label.
The charging charts below are valid for a variety of indoor,
return air conditions and are most highly influenced by
the outdoor ambient temperature, outdoor fan operation
and the unit operating voltage. Before referencing the
charts below, always ensure that all compressor circuits
are energized and have stable operation. As can be seen
in the charging charts, the ideal system sub-cooling can
vary over the range of operation. Always reference the
charts to determine the ideal amount of sub-cooling for
a given liquid pressure. Units charged to other values will
not perform at the rated unit efficiency (EER) or rated
Coefficient of Performance (COP) in heating mode.
To inspect a systems operation, using quality instruments,
match the measured liquid temperature to the units chart.
The measured liquid pressure reading should be within
3% of the value shown for most installations. For two stage
systems, the charts are valid for both compressor stages.
For systems that are operating with more then a 5%
deviation, inspect the unit for the proper voltage and phase
balance and the refrigeration system for leaks.
Units that are operating at less then 95% of the nominal
voltage or with a 2% phase imbalance may see a more
significant deviation then the amount stated above.
Always use safe and environmentally sound methods for
refrigerant handling. When repairing system leakages,
always utilize a nitrogen (inert) gas to protect the refrigerant
system and pressure check the repair before re-charging.
Always replace the filter-dryers when performing any
repair to the refrigeration system with one capable of
acid removal. After completing the repairs, evacuate the
system to 350-500 microns and weight in the refrigerant
to the amount specified on the unit rating label.
Do not use these charts for two stage systems operating only under a single stage call for cooling.
Do not use these charts in systems that do not have all the outdoor fans energized, or have the fans cycling
under a low-ambient control. Refer to the low-ambient kit instructions for more information, if applicable.