Rated Load Amps; Motor Heating Constant; Recommended Motor Heating Constant Settings - Trane RTHC Installation Operation & Maintenance

chiller with a solid state starter option, only the EA
series type starter applies. See section 3 for an
overview of the solid state starter and its settings.
Startup Contactor Test - Y-D Starters Only
This screen shall be displayed only when the starter
type is Y-Delta, otherwise this screen is skipped.
Level 2 Contactor Integrity Test:
Press (+)(-) to Change Setting
where disabled is the ROM default.

Rated Load Amps

This value should be set at the design rated load
amps as determined during the initial selection
process. If conditions change, contact Trane
Technical Support for new settings based on the new
operating conditions.
Rated Load Amps:
Press (+)(-) to Change Setting
The range of values is 0-2500 in 1 amp increments.
The ROM default is 300 amps.

Motor Heating Constant

Motor Heating Constant:
Press (+)(-) to Change Setting
The range of values XXX is 0 to 100 minutes in 1
minute increments. The ROM default is 5 minutes.
This value is used in the calculation of the restart
inhibit timer. Refer to the following table for proper
settings based on compressor size.
Table 17

Recommended Motor Heating Constant Settings

Compressor
B1
B2
C1
C2
D1
D2
D3
E3
Installation, Operation and Maintenance
[d/e]
xxxx Amps
xxx min
Motor Heating Constant
(minutes)
3
3
4
4
5
5
5
5
Current Overload Setting #1
Current Overload Setting #1:
Press (+)(-) to Change Setting
The range of values is decimal 00 through 31. The
ROM default is 00. Both the maximum acceleration
timers and the overload settings are not adjustable
from either the remote CLD or Tracer or any other
remote/external device.
The UCP2 will continuously monitor compressor
current to provide running overcurrent and locked
rotor protection. Overcurrent protection is based on
the phase with the highest current. It will trigger a
manually resettable diagnostic, shutting the unit
down, when the current exceeds a specified time-trip
curve.
The compressor overload is based on the unit RLA.
RLA is set in the UCP2 menu items along with the
current overload settings specific to a certain current
transformer (CT) and machine nameplate RLA. Use
the following procedure to set the current overload #1
and #2.
First determine the CT Factor where
CT Factor = Unit Nameplate RLA/ CT Rating x 100%
Look up the CT rating from the table below. The CT
Factor must be 66% or greater, but no more that
100% of the Nameplate RLA. Where more than one
selection is possible, use the CT rating that will give
the lowest CT Factor.
Unit Nameplate Extension
RLA (X13580269-)
33-50 -09
50-75 -10
67-100 -01
100-150 -02
134-200 -03
184-275 -04
267-400 -05
334-500 -06
467-700 -07
667-1000 -08
From the calculated CT Factor, the Motor Current
Overload Settings # 1 and #2 can be found in Table
18 following. Note that when one setting is changed,
xxx
CT Rating Amp
50
75
100
150
200
275
400
500
700
1000
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