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Manual 2100-455A
Page 17 of 25
START UP CONT’D.
SAFETY PRACTICES:
1. Never mix R-410A with other refrigerants.
2. Use gloves and safety glasses, Polyol Ester oils can
be irritating to the skin, and liquid refrigerant will
freeze the skin.
3. Never use air and R-410A to leak check; the
mixture may become flammable.
4. Do not inhale R-410A – the vapor attacks the
nervous system, creating dizziness, loss of
coordination and slurred speech. Cardiac
irregularities, unconsciousness and ultimate death
can result from breathing this concentration.
5. Do not burn R-410A. This decomposition produces
hazardous vapors. Evacuate the area if exposed.
6. Use only cylinders rated DOT4BA/4BW 400.
7. Never fill cylinders over 80% of total capacity.
8. Store cylinders in a cool area, out of direct sunlight.
9. Never heat cylinders above 125°F.
10. Never trap liquid R-410A in manifold sets, gauge
lines or cylinders. R-410A expands significantly at
warmer temperatures. Once a cylinder or line is full
of liquid, any further rise in temperature will cause
it to burst.
IMPORTANT INSTALLER NOTE
For improved start-up performance, wash the indoor coil
with a dish washing detergent.
PRESSURE SERVICE PORTS
R-410A requires high pressure hose connections and
gauges. High and Low pressure service ports are
installed on all units so that the system operating
pressures can be observed. Pressure tables can be found
later in the manual covering all models on both cooling
and heating cycles. It is imperative to match the correct
pressure table to the unit by model number.
HIGH & LOW PRESSURE SWITCH
All models are supplied with a remote reset high and low
pressure switch. If tripped, this pressure switch may be
reset by turning the thermostat off then back on again.
High/Low Pressure control provides protection for the
compressor. In the event system pressures go above 540
PSI or below 35 PSI, in either cooling or heating mode,
the compressor will be stopped. This will activate the
“L” terminal of the low voltage terminal strip. This
terminal can be used for remote indication of a pressure
lockout. The lockout circuit will hold compressor off
line. When the system problem is corrected, the unit
operation can be restored by turning the main power
supply off and then back on, or reset the room thermostat.
The low pressure control has a bypass to eliminate
nuisance lockout on cold start up.
The bypass timer should be set to 200 seconds, and this
is to assure there is no nuisance tripping of the low-
pressure control during startup in heating mode under
cold weather conditions. See Figure 10:
FIGURE 11
LOW PRESSURE CONTROL BYPASS TIMER
THREE PHASE SCROLL COMPRESSOR
START UP INFORMATION
Scroll compressors, like several other types of
compressors, will only compress in one rotational
direction. Direction of rotation is not an issue with
single phase compressors since they will always start
and run in the proper direction.
However, three phase compressors will rotate in either
direction depending upon phasing of the power. Since
there is a 50-50 chance of connecting power in such a
way as to cause rotation in the reverse direction,
verification of proper rotation must be made. All three
phase units incorporate a phase monitor to ensure proper
field wiring. See the “Phase Monitor” section later in
this manual.
Verification of proper rotation must be made any time a
compressor is changed or rewired. If improper rotation
is corrected at this time there will be no negative impact
on the durability of the compressor. However, reverse
operation for over one hour may have a negative impact
on the bearing due to oil pump out.
NOTE: If compressor is allowed to run in reverse
rotation for several minutes, the compressor’s
internal protector will trip.
All three phase ZR3 compressors are wired identically
internally. As a result, once the correct phasing is
determined for a specific system or installation,
connecting properly phased power leads to the same
Fusite terminal should maintain proper rotation
direction.