02-09-2013, 04:27 PM
Selecting and Applying Buck-Boost Transformers
Selecting and Applying Buck-Boost .pdf (Size: 134.8 KB / Downloads: 31)
United CoolAir manufactures
units that can be applied with
a variety of voltages. Some
applications utilize an input
or supply voltage of 277-1-
60. This power supply comes
from a 460-3-60 (4-wire)
system (The Neutral Leg and
the Line side opposite the
neutral leg).
While some components are
available for direct application
of 277-1-60 power, most
manufacturers (including
United CoolAir) find that
the use of a buck-boost
transformer to lower the
voltage is more cost effective.
The units are fabricated using
components suitable for 208/
230-1-60 power supply. The
control voltage transformer
is wired on the 230-volt tap
to provide the 24-volt control
voltage.
Storage
Encapsulated transformers should
be stored in a clean, dry area.
Care shoud be taken to prevent
moisture or condensation from
entering the transformer. If stored
outside, the transformer must
be covered and protected from
water, dust and other airborne
contaminants.
Electrical Connections
Refer to the transformer
nameplate label or enclosed
wiring diagram for primary and
secondary voltage combinations,
frequency and number of phases.
Tap connections and voltage
combinations are also listed on
the diagram or nameplate.
Proper assembly of the field
wiring to the transformer leads is
extremely important. Make certain
that the connector or terminal is
sized for the cable. Space and
insulate connections or terminals
per the NEC.