GE Industrial Solutions Fan Assisted Cooling (FAC) Dry-Type Transformers - Manual (Page 5)

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NOTE
AFTER INSTALLATION OF CONNECTORS AND CABLING, A MINIMUM OF 1” CLEARENCE MUST BE MAINTAINED
FROM ENERGIZED PARTS TO ALL CASE PARTS.
CAUTION
CARE MUST BE TAKEN TO PLACE ALL LEADS FROM A 3-PHASE LOAD THROUGH ONE KNOCKOUT AND THOSE
FROM THE SUPPLY/SOURCE THROUGH ONE KNOCKOUT SO THAT NO PART OF THE CASE IS BETWEEN SUCH
LEADS. IF MULTIPLE KNOCKOUT HOLES ARE REQUIRED, EACH KNOCKOUT HOLE MUST CONTAIN THE SAME
NUMBER OF CABELS ROUTED TO EACH PHASE OF THE TRANSFORMER. FAILURE TO DO SO CAN CAUSE
EXCESSIVE HEATING OF THE TRANSFORMER ENCLOSURE. TO PREVENT ENCLOSURE DAMAGE, PROVIDE
PROPER SUPPORT OF TRANSFORMER ENCLOSURE PANELS WHEN PULLING CABLES THROUGH PANEL.
6.2 Grounding
Consideration must be given to equipment grounding. Grounding methods and practices are well established and are beyond the
scope of this installation guide. The grounding conductor for a transformer should have a current carrying capacity in accordance
with the NEC. Refer to enclosure assembly picture on last page.
6.3 Lighting Tap Applications
Some transformers with a 240-volt delta connected secondary have a 120-volt single-phase lighting tap. The maximum single-phase
120-volt load should not exceed 5% of the three-phase kVA rating. The load should also be balanced at 2.5% maximum between
terminals X1 to X4 and 2.5% between terminals X3 to X4. Please note that fans obtain power from the secondary of the
transformer. On delta-wye transformers the fans will be connected to X0, X1, X2 and X3 while on delta-delta transformers they will
be connected to X4, X1 and X2 where X4 designates the lighting tap.
6.4 Fans, Alarm and Shunt
Terminal on Block Significance if terminal has 120 volts.
Contact “6” Fans on phase 1 are running.
Contact “7” Fans on phase 2 are running.
Contact “8” Fans on phase 3 are running.
Contact “9” Alarm has been activated.
FAC units contain safety features to prevent overheating. An
audible alarm will sound when temperatures are over design
limits. If temperatures reach a critical point, a three-phase
disconnect (included on the primary side) will be activated
and all power will be shut off. For remote monitoring, the
following contacts on the terminal block will have 120 volts
(reference to Contact 1 on Terminal Block) when active and
0 volts when not active.
Contact “10”
(pulse only)
Three-phase disconnect has been
activated (power turned off).
The fans, alarm and shunt that activates the three phase disconnect on FAC units are pre-wired in the factory and obtain power from
the secondary of the transformer.
7.0 Before Energizing
Visually inspect all parts of transformer for proper operation. Fans must not be obstructed, lever on three-phase disconnect must be
in raised position and noise insulation material must be adjacent to enclosure panels. Complete all connections to main harness if
remote monitoring is desired.
8.0 Operation
To maintain safe operating conditions do not remove panels of the enclosure while the transformer is energized.
CAUTION
NEVER ATTEMPT TO CHANGE TAPS OR CONNECTIONS UNLESS THE TRANSFORMER IS DE-ENERGIZED AND
ALL WINDINGS GROUNDED.
NOTE
TRANSFORMERS RUN HOT: AT FULL LOAD, TRANSFORMERS COULD HAVE A MAXIMUM 50C/122F
TEMPERATURE RISE ON THE SURFACE AREAS OF THE ENCLOSURE. WITH A 40C AMBIENT, THE MEASURED
TEMPERATURE COULD BE AS HIGH AS 90C/194F.