Hammond Power Solutions Indoor/Outdoor Encapsulated Transformers Installation Guide
INSTALLATION, OPERATION AND MAINTENANCE GUIDE
FOR INDOOR/OUTDOOR SINGLE PHASE
FOR INDOOR/OUTDOOR SINGLE PHASE
ENCAPSULATED TRANSFORMERS
ENCAPSULATED TRANSFORMERS
Indoor/Outdoor
Encapsulated Transformers
Single Phase
Up To 50 kVA
*Note: This guide is Trilingual
(English, French, Spanish)*
Literature No.: IOMGE1PH
Issue Date: May 2010
Safety Precautions
(1) Do not lift or move a transformer without proper equipment and
experienced personnel.
(2) Do not install the transformer until a full inspection has been
completed.
(3) Use terminals only for electrical connections, and exible connectors
are recommended.
(4) Connections should only be in accordance with the nameplate diagram
or connection drawings.
(5) Make sure all power is disconnected before attempting any work on the
transformer.
(6) Make certain all ground connections are complete and tightened before
energizing the transformer.
(7) Do not attempt to change any taps - primary or secondary, while the
transformer is energized.
(8) Do not change connections when the transformer is energized.
(9) Do not adjust or remove any accessories or cover plates while the
transformer is energized.
Class 1, Division 2, Hazardous Location
Installation Requirements
If this unit is designed for use in Class 1, Division 2, Groups A, B, C & D
hazardous locations then also refer to notes below:
(1) Power, input and output (I/O) wiring must be in accordance with Class 1,
Division 2 wiring methods as per Article 501-10 (b) of the National
Electrical Code.
(2) WARNING - EXPLOSION HAZARD - DO NOT DISCONNECT EQUIPMENT
UNLESS POWER HAS BEEN SWITCHED OFF OR THE AREA IS KNOWN
TO BE NON-HAZARDOUS.
CONTENTS
General Information 3
Handling 3
Receiving & Inspection 3
Storage 3
Installation 3
Ventilation 4
Accessibility 4
Sound Levels 4
Cable Connections 4
Grounding 4
Inspection Before Energization 5
Operation 5
Maintenance 5
Diagrams 1a, 1b and 2 6
- 2 -
INSTALLATION, OPERATION AND MAINTENANCE
OF ENCAPSULATED TRANSFORMERS
GENERAL
Encapsulated transformers are manufactured to
provide optimum performance for a lifetime of
uninterrupted service. Careful attention to the following
instructions is recommended for safe and reliable
operation.
Installation, operation and maintenance of
transformers should be performed by qualied
persons, familiar with electrical apparatus and the
potential hazards involved.
Warning: Danger! There is the potential of electric
shock whenever working in or around electrical
equipment such as transformers. Power must
be shut off before any work is conducted on a
transformer.
As with any electrical device, transformers
must be installed according to the requirements
of the national, and local electrical codes. Refer
to ANSI/IEEE C57-94 may also be referred to for
recommended installation, application, operation and
maintenance of dry-type transformers.
STORAGE
Transformers that will not be immediately
installed and energized, should be stored in a clean
dry environment away from any environmental
airborne contaminants.
It is recommended that transformers be stored in
a heated building, in the original shipping packaging.
INSTALLATION
All encapsulated transformers are supplied with a
NEMA 3R enclosure. NEMA 3R units may be installed
indoors, or outdoors where applicable.
For any outdoor location, the appropriate
applicable codes must be followed including cable
installation and hardware suitable for outdoor service.
Water tight couplings must be used at the knockouts.
Encapsulated transformers must be located in
an upright position on walls, posts, beams or other
locations capable of supporting their weight.
If encapsulated units are to be either stored or
installed outdoors, the unit must be oriented vertically
with the wiring compartment down to prevent the
ingress of moisture.
HANDLING
Transformers are either shipped in cartons or
palletized. The units on pallets can either be lifted via a
forklift truck or hoisted by the lifting lugs provided.
Appropriate lifting equipment should be used
relative to the size of each transformer. No attempt
should be made to lift or move a transformer from any
points on the unit other than those indicated.
Please Note: On units bolted to the pallets,
please remove the shipping bolts located at the top
mounting holes as well as the one(s) located inside the
wiring compartment.
RECEIVING INSPECTION
Immediately after receiving the transformer, it
should be inspected for any transit damage and for
correctness against the shipping documents.
The unit should be examined for any breaks in its
packaging, dented or damaged enclosures or missing
parts from the packing list.
If any damage is noted, a claim should be led
immediately with the carrier and a second copy of
all pertinent information relative to the order and the
circumstances should be led with the local sales
ofce.
Mounting Instructions (refer to page 6)
1. Select an installation location that is on a
non-combustable surface.
2. The mounting location must allow for air
circulation around the transformer for cooling
purposes. Please refer to the minimum distances
stated in the ventilation section.
3. Using the appropriate mounting template
provided, drill the top two mounting holes on the
mounting surface.
4. Lift the transformer into position and install the top
two mounting bolts.
5. With the transformer hanging on the top two
mounting bolts, level the unit, then with the wiring
compartment cover open, mark and drill the lower
mounting hole(s) into the mounting surface.
6. To provide NEMA 3R protection (protection from
falling rain), the transformer must be mounted
vertically with the mounting tabs facing up.
7. Install the lower mounting bolt, lock washer, at
washer and rubber washer into the lower
mounting hole(s) (refer to Diagram 2).
- 3 -
VENTILATION
CABLE CONNECTIONS
Transformers are required to be installed in
an area where they can be cooled by means of the
free circulation of air where the average ambient
temperature is 30°C (86°F) and should not exceed
40°C (104°F) at any time.
Adequate ventilation is essential for transformers
to meet their nameplate kVA capability. All
encapsulated general purpose transformers should be
located at least 2 inches on units up to 10kVA and at
least 4 inches on units over 10kVA, away from walls or
any other obstructions to allow free, clean circulation
of air.
ACCESSIBILTY
accessible for inspection and located accordingly.
However, transformers should not be located in areas
where stored items are likely to interfere with either
natural air convection or the capability to have them
inspected. Passage ways or other areas where people
could be exposed to live parts during inspection should
also be avoided.
Adequate protection should be provided under
any circumstances.
NEC standards require that transformers be
1. Open the wiring compartment by loosening the
cover screw.
2. Terminals should be cleaned and electrical joint
compounds are recommended for use on all
electrical connections.
3. Make the appropriate electrical connection to suit
the desired voltages as per the connection
diagram on the nameplate. This includes the
input connections, output connections and the
ground(s).
WARNING: If this unit is designed for and to be
used in Class 1, Division 2, Groups A, B, C and
D hazardous locations than the power, input and
output (1/0) wiring must be in accordance with
Class 1, Division 2 wiring methods as per Articles
501-10 (b) of the National Electrical Code.
4. Make certain to insulate any unused wire leads
with marrette connectors and electrical tape.
5. Close the wiring compartment and ensure that
the cover screw is tightly secured.
TRANSFORMER SOUND LEVELS
Transformers are an electrically energized
apparatus and by their nature emit sound due to their
component materials.
Transformers are required to meet NEMA
standards for the maximum sound levels permissible.
These sound level standards vary from 40 to 60 DB
and hence, can be an annoyance if located in close
proximity to where people work or reside.
Care should therefore be exercised in selecting
sites for transformers particularly to avoid sensitive
areas like hospitals, classrooms, medical or ofce
facilities.
The following guide lines may be helpful;
Units should be mounted away from corners or
reecting walls or ceilings.
Cable or other exible conduit should be
considered to make connections.
Acoustically absorbing materials could be
considered for walls and ceilings around the unit.
The location of the unit should be located as far
as practical from areas where sound levels could
be considered undesirable.
The connecting cable size is determined from
the line current rating of the transformers primary
and secondary windings. Convenient pre-punched
knockouts are provided on all transformer enclosures,
to facilitate cable entry. (NOTE: potted transformers cannot be
returned if the knockouts have been removed unless the unit has a
manufacturing defect as outlined in the standard warranty policy.)
GROUNDING
All core and coil assemblies are solidly grounded
to the enclosure internally to ensure that all conductive
metal parts have the same potential.
The transformer enclosure in turn should also
be securely and effectively grounded as a safety
precaution. This grounding should be in accordance
with national electrical code standards.
- 4 -
INSPECTION BEFORE ENERGIZATION
For the safe and proper operation of the
transformer, we recommend that the following items be
checked for completeness:
a) The insulation resistance, enclosure to primary,
enclosure to secondary and primary to
secondary, should be greater than 10k ohms.
b) Before energizing and connecting any loads,
please measure and verify the output voltage
matches nameplate specications.
c) Ensure correct phase connections. Refer to the
nameplate vector diagram.
d) When windings are connected in parallel (as in
the case of dual voltage primaries), the primary
taps for all coils must be connected to the
identical percentage tap positions to avoid the
shorting of turns. For tap positions, refer to the
nameplate on the transformer.
e) The enclosure should be grounded with the
appropriately sized conductor.
f) The clearance and tightness of all electrical
connections should be checked.
g) For single phase 3-wire 240/120 volt loads, care
must be taken to ensure the neutral current does
not exceed 1/2 of the transformers kVA rating.
OPERATION
For all relatively normal and clean installations,
encapsulated transformers will operate satisfactorily
under normal conditions of energization and load.
For your reference, fully loaded transformers may
be very warm to the touch, particularly on the top of
the unit.
Standards permit the temperatures of the
enclosure to be 65°C over ambient. This represents
normal loading and should not be of concern.
Encapsulated transformers are designed to
operate continuously at their full nameplate kVA rating.
ANSI C57.96 provides guidance for loading
transformers under different conditions including:
Ambient temperatures that are varied from the
ambient temperatures required for transformer
operation.
Short time overload as it relates to time and
temperature and the corresponding loss of life of
the transformer.
Overload that results in a reduction of life
expectancy of the transformer.
If the transformer is experiencing increased
temperatures, the following load characteristics
should be considered immediately:
Rigorous motor starting loads or other impact
type loading for which a specic transformer for
that application is required.
Over-excitation of unit due to excess supply line
voltage or current.
Ambient temperatures above standard.
Overload beyond ANSI C57.96 guidelines.
Harmonic distortions of the supply line voltage
and currents.
MAINTENANCE
Under normal operating conditions and
environments, encapsulated transformers do not
require maintenance. However, periodic care and
inspection is a good practice, particularly if the unit is
exposed to extreme environmental conditions.
Peripheral inspection and external dust and dirt
removal may be carried out while the transformer is
in operation. However, access covers must not be
opened under energized conditions.
The accumulation of ice or snow will not adversly
effect the operation of encapsulated transformers.
However, the accumulation of dust or dirt will effect the
cooling of the transformer and may become a potential
fire hazard.
Internal maintenance must be performed with a
transformer de-energized, isolated and with the
terminals grounded.
The ground connection should be checked to
ensure a low impedance connection.
WARNING: If this unit is designed for and to be
used in Class 1, Division 2, Groups A, B, C, and
D hazardous locations; DO NOT DISCONNECT
EQUIPMENT UNLESS POWER HAS BEEN
SWITCHED OFF OR THE AREA IS KNOWN TO BE
NON-HAZARDOUS
- 5 -
Upper
Mounting
Holes
Upper
Mounting
Holes
FRONT VIEW SIDE VIEW BACK VIEW
Side Knockout Rear Knockout
Wiring
Compartment
Cover
Wiring
Compartment
Cover
Screw
Mtg. Hole
Lower
Mounting
Hole(s)
(see diagram 2 below)
DIAGRAM 1a: NQ0, NQ1, NQ2, NQ3, NQ4 and NQ5 Series Enclosure Mounting for
Upper
Mounting
Holes
Upper
Mounting
Holes
FRONT VIEW SIDE VIEW BACK VIEW
Side Knockout
Rear Knockout
Wiring
Compartment
Cover
Mtg. Hole
Mtg. Hole
Lower
Mounting
Hole(s)
Wiring
Compartment
Cover
Screw
Lifting Tabs
(see diagram 2 below)
Trans former
Enclo sure
Mount ing
Bolt
Lock
Washe r
Flat
Washe r
Rubbe r
Washe r
Single Phase Encapsulated Transformers.
DIAGRAM 1b: NQ6, NQ6A, NQ7 and NQ8 Series Enclosure Mounting for Single Phase
Encapsulated Transformers.
DIAGRAM 2: Lower wiring compartment mounting hole(s), mounting hardware installation
assembly diagram.
- 6 -
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