Thermal Overload; Current Imbalance (Loaded & Unloaded); Loss Of Phase; Improper Phase Sequence - York YCAS Installation Operation & Maintenance

Anytime a dip switch change is made,
pow er must be cycled off and on to
the module to re pro gram the mod ule
to the new value.

Thermal Overload

Three PTC (positive temperature co ef fi cient) ther mistors
in the motor windings provides thermal pro tec tion. The
sensor re sis tance stays rel a tive ly con stant at 1k
a tem per a ture of 266°F (130°C) is sensed. The sensor
ex pe ri enc es a rapid rise in re sis tance be yond this
tem per a ture. When ev er the re sis tance of one of the
Ω, ± 3
sen sors reach es 13k k
which ul ti mate ly de-energizes the mo tor's pi lot cir cuit.
Re set is manual after the mo tor cools and the sen sor
Ω
re sis tance drops to 3.25k
Current Imbalance (Loaded & Unloaded)/

Loss of Phase

A 2 second delay at start-up allows for any imbalances
resulting during normal starting conditions. After
this ini tial delay, the 2ACE module compares the
"Op er at ing Current" to the measured half line current.
The "Op er at ing Current" is given by 0.65 X factory
overload cur rent setting.
YORK INTERNATIONAL
Ω
until
Ω
, the 2ACE module trips,
0.5 Ω.
, ± k
An unloaded compressor condition occurs when any
measured half line current is less than the "Operating
Current." A current imbalance exceeding an unloaded
level of 25% will result in the motor pilot circuit being
de-energized.
A loaded compressor condition occurs when any
mea sured half line current is great er than or equal to the
"Operating Current." A cur rent imbalance exceeding a
loaded level of 17% will result in the motor pilot cir cuit
being de-energized.
Imbalance is defi ned as
(High Phase - Low Phase)/High Phase

Improper Phase Sequence

The 2ACE module calculates the phase sequence at
start-up using the three cur rent transformers to de ter mine
wheth er the three phase sequence on the load side of
the main contactor is miswired. Upon de tec tion of
a miswired motor load, the mod ule will de-energize
the main contactor pi lot circuit within 50 millisecond
re sponse time.
Additional information on the 2ACE MP module may
be found on page 138.
FORM 201.19-NM6 (804)
2
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