LARSON MT-BBT-480Y-380Y.220-3P-781A, Руководство пользователя

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DIAGRAM L
BUCK & BOOST TRANSFORMERS
Ventilation
Transformers are required to maintain free air flow around the unit for cooling purposes. The location should
maintain an average ambient temperature of 86°F (30°C) and should not exceed 104°F (40°C) at any time.
Proper ventilation is essential for transformers to meet their kVA capability. General purpose transformers
should be located at least 2 inches for 10kVA and 4 inches for units over 10kVA from the surface to maintain
adequate air circulation.
Accessibility
Due to NEC standards, it is required for transformers to be accessible for inspection and located accordingly.
Exposed passage ways where people could be exposed to live parts during inspection should be avoided.
Sound Levels
By nature, transformers emit sound frequencies due to their electrically energized components. Care should be
exercised when selecting a location to avoid sensitive areas such as in schools, hospitals, and office facilities.
The sound levels produced by these transformers are required to meet NEMA standards. The sound level can
vary from 40 to 60 DB. Acoustically absorbing materials could be considered for surrounding walls and
ceilings.
Wire Connections
1. Loosen the cover screw on the front to open the wiring compartment.
2. Ensure terminals are clean. Use the included lugs and bolts for terminal wiring where applicable. Use
wire nuts or similar for all other electrical connections.
3. Make the required electrical connections per the wire diagram on page 4-6. This includes input and
output connections, as well as ground(s).
4. If any unused wire leads remain, insulate with wire nuts and electrical tape.
5. Inspect all connections and close the wiring compartment. Secure the cover screw.
Proper cable size is selected based on the line current rating of the transformers primary and secondary sides.
Pre-punched knockouts are provided to help facilitate cable entry.
Ground
Grounding should be done in accordance with national electrical code standards. Securely grounding the
transformer should be done as a safety precaution.
For safe and proper operation of the transformer, we recommend the following items be checked for
completeness:

Insulation resistance: enclosure to primary, enclosure to secondary and primary to secondary should be
greater than 10k ohms.

Output voltage: measure and verify that the transformer outputs the correct voltage in accordance with
nameplate specifications. Voltage may vary depending on actual power available at your facility.

Phase connections: refer to the nameplate diagram to ensure correct phase connections.

When windings are connected in parallel (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 transformer nameplate.