IB140015EN
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Instructional Booklet
Effective: August 2014
Page
19
ATC-900 Magnum Tranfer Switch O & M Manual
4.6 Voltage Selection Adjustment (Non-Connector)
Certain devices, such as the voltage selection panel, sensing
relays, and timers need to be set and/or calibrated prior to placing
the transfer switch equipment into service. Adjustments for logic
devices are described in the separate instructional document dedi-
cated to the specific logic being used. Voltage selection adjust-
ments are described here. For newer switches (Nov 2014) there is
a voltage selection connector. Please see section 3.3.1 for the
voltage selection types. If the voltage selection is not on the front
of the transformer using a connector, then one would need to
open the transformer and move the physical tap connectors. The
following is how to change the taps.
Voltage selection is made at the multi-tap transformer subassem-
bly (see Figures 22, 22A, and 22B) mounted in the lower compart-
ment of the transfer switch. This subassembly includes two
identical control power transformers with one connected to
Source 1(NT1) and the other connected to Source 2 (ET1). The
control power transformers are mounted behind a removable panel
(see Figure 22B).
Figure 22.Transformer and Taps.
Figure 22A.
Figure 22B.
•
Remove the transformer pack cover by loosening the 4 screws
located at each corner of the transformer pack assembly.
•
The transformers are factory set on the voltage tap specified by
the customer. (See illustration above for location of various
taps and voltages)
•
Detach the spade connector from the existing voltage tap and
place on the tap that is suitable for your application.
.
•
After changing the taps on both transformers, replace the trans-
former pack cover and tighten all four screws.
PRIMARY
TERMINALS
SECONDARY
TERMINALS
415V 6
380V 5
240V 4
220V 3
208V 2
0V 1
50/60Hz
12
11
10
9
SECONDARY 1
120V, 300VA
INTERMITTENT 50%
DUTY CYCLE
SECONDARY 2
120V, 25VA
7
9
10
11
12
120V, 25A
12
11
9
10
120V 300VA
TOP: 7-480V 5-380V 3-220V 1-COMMON
BOTTOM: 8-600V 6-415V 4-240V 2-208V
5
3
8
6
4
480V 7
600V 8
1
2
1268C19G07
Primary Side Connections:
Connection 1 - Tap on #1 Common
Connection 2 - Tap on the nominal
system voltage
WARNING
DISCONNECT ALL SOURCES OF POWER OR DISCONNECT P7/S7
PRIOR TO PERFORMING THE FOLLOWING. FAILURE TO DO SO MAY
CAUSE SERIOUS INJURY OR DEATH.
CAUTION
BE SURE THAT THE CORRECT VOLTAGE IS SELECTED TO MATCH
THE SYSTEM VOLTAGE. AN IMPROPER SELECTION AND/OR CON-
NECTION COULD RESULT IN EQUIPMENT DAMAGE.
