Compressor Motor Protection - Carlyle 06D Series Application Manual

In cases where an 06D compressor is applied without
the supplementary overloads, the use of approved cali-
brated circuit breakers is required. These circuit break-
ers must trip at or under the maximum continuous cur-
rent (MCC) level listed in Table 5 on Page 36, and under
the locked rotor conditions within 2 to 6 seconds.
Carlyle-approved circuit breakers can use the 140% or
156% factor to determine RLA values. When approved
circuit breakers are used, the must trip ampere value of
the circuit breaker becomes the MCC value of the com-
pressor branch circuit. This can be used to determine
the new compressor branch circuit RLA value.
Thermal Protection
Internal thermostats are also supplied with all 06D com-
pressors with the only exception being part-winding start
models. These thermostats are embedded in the motor
windings with contacts rated at 240VA that open on tem-
perature rise and close on temperature fall. When wired
into the control circuit the 240VA rating should not be
exceeded. Due to its small mass and the low temperature
rise rate of the 06D motors, these thermostats follow
motor temperatures closely and provide complete ther-
mal protection. Thermostat connections are made at ter-
minals #8 and #9 on the compressor terminal block in
the terminal box. The thermostats are pilot duty, auto-
matic reset devices.
Branch Circuit Protection
Branch circuit protection may be obtained by use of time
delay fuses as noted in the electrical table or by circuit
breakers selected at 110% to 125% of compressor
motor overload trip current or maximum continuous
current valves shown in Table 5. These circuit breakers
or fuses should not be selected at trip settings less then
the MCC (Maximum Continuous Current) values shown
in Table 5.
4.2 06E Compressor Motor Protection
The 06E compressors must be applied with properly
sized calibrated circuit breakers to protect the motor
against overcurrent fault conditions.
Primary Motor Protection
Calibrated circuit breakers must be provided for over-
current protection. Approved circuit breaker selections
are shown in Tables 6 - 9 (Page 27 and 28) for the
06EA, 06ER and 06EM compressors. Use of circuit
breakers other than those shown in this
Application Manual, or any other alternate over-
current protection must be approved by Carlyle
Application Engineering - otherwise compressor
warranty will be voided. For proper overcurrent pro-
tection, the must trip setting of the calibrated circuit
breaker must not exceed the compressor Maximum
Must Trip Amps shown in Tables 6 - 9. The selected
compressor overcurrent device must trip in 2 to 6 sec-
onds at the LRA value shown for the compressor.
The circuit breakers selected by Carlyle are manually
reset and have been sized to protect the compressor
against running overcurrent, locked rotor, primary and
secondary single phasing. These circuit breakers also
offer the additional advantage of protecting the compres-
sor against malfunctions of the compressor contactor
(which may not be possible with pilot duty motor
protection).
Table 9 shows the part winding (PW) 6 pole circuit
breakers selected for 208/230 volt, three phase, 60 hertz
applications. The selected compressor overcurrent pro-
tection device for part winding must trip the first 3 legs
in 2 to 6 seconds and the second 3 legs in 1 to 3 sec-
onds. Carlyle recommends a 1 to 1.25 second time delay
between energizing the first and second legs. These cir-
cuit breakers are stocked in limited quantities by Carlyle.
Other 6 pole, part winding circuit breakers with different
trip settings or for other voltages are also available but
may require special order.
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