Filtec FT-70c, Service And Technical Reference Manual

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Chapter 3: Installing the FT-70
3-27
Example B: Using a Voltage Regulating Transformer
If voltage stability is a problem, a voltage regulating type trans-
former should be used. This example uses a transformer to isolate
the FT-50 and to convert the line voltage to the proper voltage for
the FT-70.
1. The secondary side of the transformer must be connected to the
hot and neutral wires in the FT-70. It makes no difference
which wires from the secondary attach to input wires in the
FT-70, but if color coded wires are used, connect white to
neutral.
2. Do not connect the transformer secondary terminals to the
neutral on the primary because it negates the isolation
properties.
3. Connect the FT-70 ground stud to the facilities ground system.
The neutral wire should also be connected to this ground stud.
4. If the transformer has an internal electrostatic shield, ground it
to the Earth ground if possible (however the FT-70 ground is
suitable). This shield may be attached to the transformer case
in some units, or it may have a separate wire lead. Examine the
transformer carefully to determine if it is shielded and, if so,
ground the shield.
Figure 3-25. Main power wiring Example B.
115, 23O,
440, etc.
1Ø
115/230 VAC
6
4
1
115 230 2
3
N
7 8
9 10
H
5
No. Description
1 FT-70 Power Junction Box
2 Voltage Switch Proper Voltage
3 Connect FT-70 pigtail leads to
input power wires
4 FT-70 Ground Stud
5 External Breaker or Disconnect
6 Separate Transformer
7 White
8 Blue
9 Black
10 Brown
Industrial Dynamics Company, Ltd. © Form
40256-0600