Carrier 19XL - Manual (Page 48)

Circuit breaker CB2 supplies power to the control center, oil heater, and portions of the
starter controls. Circuit breaker CB3 supplies power to oil pump. Both of these circuit breakers
are wired in parallel with CB1 so that power is supplied to them if the CB1 disconnect is open.
All starters are shipped with a Carrier control module called the Starter Management Module
(SMM). This module controls and monitors all aspects of the starter. See the Controls section
for additional SMM information. All starter replacement parts are supplied by the starter
manufacturer.
Unit-Mounted Solid-State Starter (Optional)
The 19XL may be equipped with a solid-state, reduced-voltage starter ( Figure 5 , Figure 6 ,
Figure 7 ). This starter provides on-off control of the compressor motor as its primary function.
Using this type of starter reduces the peak starting torque, reduces the motor inrush current,
and decreases mechanical shock. This is summed up by the phrase ‘‘soft starting.’’
Two varieties of solid-state starters are available as a 19XL option (factory supplied and
installed). When a unit-mounted, optional, solid-state starter is purchased with the 19XL, either
a Benshaw, Inc. or Cutler-Hammer® solid-state starter will be shipped with the unit. See
Figure 5 and Figure 6 . The solid-state starter’s manufacturer name will be located inside the
starter access door. See Figure 7 .
These starters operate by reducing the starting voltage. The starting torque of a motor at full
voltage is typically 125% to 175% of the running torque. When the voltage and the current are