SECTION
ACME ELECTRIC
•
MILWAUKEE, WI
•
800.334.5214
•
acmetransformer.com
44
DRIVE ISOLATION TRANSFORMERS
Drive Isolation Transformers
Stress relief
Acme uses strip conductors (above 7.5 kVA)
instead of wire for a DIT series that easily
accommodates the severe electrical and
mechanical stresses found in today’s AC & DC
motor drives. The inherent excellent line isolation
of these transformers is further enhanced with
the extra protection of Acme’s Electrostatic
Shield — free in all DIT’s.
Lower losses
The harmonic currents generated by AC & DC
drives increase eddy current losses (heat) in
transformer windings. The thicker the winding
conductor, the greater the losses. Acme uses
one turn per layer of thin strip conductor which
provides lower eddy current losses than
comparable wire wound units. Lower losses =
cooler operation and longer transformer life.
DTGB0404S
DTGA72S
DTGA0142S
DTHA03304S
The Acme Drive Isolation Transformers are spe-
cifically designed to accommodate the
special voltages and kVA sizes unique to AC and
DC motor drive applications.
FEATURES
n
UL Type 3R Enclosures with Weather Shield
on Ventilated Units (above 20 kVA).
Type 2
Enclosure without weather shield. UL Listed and
CSA certified. 7.5–20.0 kVA are encapsulated,
UL 3R.
n
3-Phase 60 Hertz.
n
180°C and 220°C insulation systems.
n
Encapsulated and ventilated designs. All
ventilated units, are of strip wound construction.
Acme’s reinforced core assemblies enhance
quiet operation.
n
Nominally 6% impedance.
n
Designed for use with AC, adjustable frequency
or DC drives.
n
Full capacity taps are featured on all units. On
7.5 through 20 kVA units, taps are 1-5% ANFC
and 1-5% BNFC. On 27 through 660 kVA units,
taps are 2-2
1
/
2
% ANFC and 2-2
1
/
2
% BNFC.
n
Full range of kVA ratings cover all standard
drive systems.
n
Ample wiring compartment for easy cable entry.
n
Optional wall mounting brackets for certain sizes.
Reduced short
circuit forces
Strip windings minimize axial
short circuit forces that can cause
mechanical displacement of the
windings under fault conditions.
For extra protection all designs 7.5
kVA and above use primary and
secondary coils of equal axial length.
This feature tends to negate axial
short circuit forces, further improving
transformer life expectancy.
Selection
instructions
If you know the motor horse-power,
simply follow the drive system
manufacturer's recommendation. Or,
select the corresponding kVA from
the chart at right.
For example, a 40 Hp motor requires a
51 kVA DIT.
H.P.
kVA
5.0
7.5
7.5
11.0
10.0
14.0
15.0
20.0
20.0
27.0
25.0
34.0
30.0
40.0
40.0
51.0
50.0
63.0
60.0
75.0
75.0
93.0
100.0
118.0
125.0
145.0
150.0
175.0
200.0
220.0
250.0
275.0
300.0
330.0
400.0
440.0
500.0
550.0
600.0
660.0
