Eaton Cutler-Hammer AMPGARD Technical Data Manual page 12

AMPGARD IT. Soft Start (Continued)
Settings are selected via DIP switches on the operator interface
located behind the low voltage door on the lower compartment.
Lower Compartment Low Voltage Door
Load Cables — Normal
Load Cables — Moved for Full Voltage Start
CIM Operator Interface
12 EATON CORPORATION Cutler-Hammer Chiller Starter (AMPGARD) Technical Data TD02003003E Effective: October 2006
The pole units include an integrated run contactor and are rated 2500
volts per set. One set is required for systems up to 2500 volts and
two sets in series are required for systems up to 5000 volts.
2500 Volt Pole Unit
Pole units are mounted in a easy-to-remove rollout truck assembly.
Maintenance can be performed with the truck on a bench away from
the starter cubicle.
Rollout SCR Truck
How IT. Works
1. Industry exclusive integral run contactor dramatically reduces
overall size of starter.
2. Run contactor is open, all current passes through the SCRs and
voltage is reduced per program requirements.
3. After start is complete, the run contactor closes, then the SCRs
are turned off (closed transition).
4. The SCRs are on only a short time therefore no MCC venting or
cooling is required.
5. Because the run contactor never sees the in-rush current, it is
sized only for full load amperes.
If maintenance or repair of the SCR truck is required, it can be quickly
removed and the motor can be started at full voltage by two methods.
Method one is to move the lower compartment load cables from the
load stabs to the line stabs (see photo). Method two is to install the
optional bypass truck.
Bypass Truck