Ingersoll-Rand ReliaTel, Manual, Page: 74 / 176

74 RT-SVD03L-EN
Evaporator Coil Frost Protection
When the OA temperature is less than 55°F (single
compressor) 40° F (multi-compressor) the unit will
enable the evaporator coil frost protection function.
This function will cycle all compressors off every 10
minutes of continuous operation. For the variable
speed compressor the shutdown and startup
sequences will be incorporated into the timing
extending the total variable speed compressor ON time
to 10 m shutdown sequence time before
shutting off.
Extended Time at Compressor Low
Speed (Oil Recovery Mode)
• For 3–5T & 12.5–17.5T units: If the VSPD
compressor operates for 19 continuous minutes
with active compressor speed
< 40Hz, the VSPD
compressor shall ramp to 40Hz for minimum of 1
minute and then will be released back to normal
operation.
• For 6–10T units: If the VSPD compressor operates
for 19 continuous minutes with active compressor
speed
< 45Hz, the VSPD compressor shall ramp to
45Hz for minimum of 1 minute and then will be
released back to normal operation.
High Ambient Operation Protection (3–
5T & 12.5–17.5T eFlex
™ ™ Units)
If the OA temperature reaches temperature in excess of
100°F, ReliaTel
™ controls will implement minimum
and maximum compressor speed limits. The limits are
shown in the following table.
Table 30. Speed limits
Entering
Outdoor
Ambient
(deg F)
RPM
Lower
Limit
(RPM)
RPM
Lower
Limit
(Hz)
RPM
Lower
Limit
(V)
RPM
Upper
Limit
(RPM)
RPM
Upper
Limit
(Hz)
RPM
Upper
Limit
(V)
100 1100 18 2.7 4500 75 6.8
107 1300 22 2.9 4500 75 6.8
112 1500 25 3.2 4200 70 6.4
118 1800 30 3.5 3600 60 5.7
124 2100 35 3.9 3000 50 5
127 2400 40 4.3 2400 40 4.3
Note: As OAT decreases, leaving each condition occurs at an
OAT of 2°F below the entering OAT temperature specified
in the table.
Precedent ™ ™ 6T-10T eFlex ™ ™ Emerson
Compressor Enabled Units
On eFlex units incorporating an Emerson compressor,
a condensing temperature sensor and evaporator
temperature sensor will be used to control the
minimum compressor speed within the limits of the
compressor operating map. This operating map control
will not be active during AHRI test mode. These
minimum compressor speed limitations are defined in
the following table.
Table 31. Compressor speed limit — Precedent ™ ™ eFlex ™ ™ 6–10 Tons
Unit
Evap Temp (deg F) Cond Temp (deg F)
RPM
Lower
Limit
(RPM)
RPM
Lower
Limit (Hz)
RPM
Lower
Limit (V)
RPM
Upper
Limit
(RPM)
RPM
Upper
Limit (Hz)
RPM
Upper
Limit (V)
6 Tons
Temp > 65F any
2700 45 3.75 5000 83 6.92
20F ≤ Temp < 65F (a)
temp ≥ 125F
2700 45 3.75 5000 83 6.92
95F ≤ temp < 125F (b)
1680 28 2.33 5000 83 6.92
temp < 95F (b)
1020 17 1.42 5000 83 6.92
7.5 to 10
Tons
Temp > 60F any
2640 44 3.67 6000 100 8.33
Temp < 60F (a)
temp ≥ 130F
2220 37 3.08 6000 100 8.33
95F ≤ temp < 130F (b) 1800 30 2.5 7200 120 10
temp < 95F (b)
1320 22 1.83 7200 120 10
Note: If any of the EvapTemp and CondTemp senor fails, operation outside the limitations of the operating map cannot be guaranteed. The compressor will
not operate.
(a) As the EvapTemp decreases, leaving each condition occurs at a temperature of 8 deg F below the entering EvapTemp specified in the table.
(b) CondTemp decreases, leaving each condition occurs at a temperature of 5 deg F below the entering CondTemp temperature specified in the table.
Compressor Protection
The connections for compressor proving and low
pressure cutout for the VSPD compressor are on the
VSM module. On multi-compressor units, each
compressor will have its own compressor proving
input, but will have one compressor disable input per
refrigeration circuit.
If the case of compressor failure the following
sequences will be used based on the compressor(s)
failed:
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