Powering the MultiFlex CUB Board
Mounting and Powering • 5
2.3.2.1.
New-Style MultiFlex CUB Boards
(With Isolated Power Supply)
The new-style MultiFlex board can be con-
nected to any of the center-tapped transformers
mentioned in
Table 2-2
, provided the 0V termi-
nal of the board is connected to an earth ground.
A center-tapped transformer may power
both center-tapped and non-center-tapped
devices at the same time, as long as
none of the
non-center-tapped MultiFlex boards are old-
style MultiFlex boards.
If an old-style Multi-
Flex shares the same center-tapped transformer
as a device that uses the center tap, the old-style
MultiFlex will be damaged.
Figure 2-5
shows
how to wire a non-center-tapped device to a cen-
ter-tapped transformer.
In addition, the MultiFlex CUB boards can
be powered by one of the 50VA or 75VA non-
center-tapped transformers listed in
Table 2-1 on
page 3
.
Figure 2-6
shows how to wire the trans-
formers to the MultiFlex boards.
2.3.2.2.
Old-Style MultiFlex CUB Boards
(No Isolated Power Supply)
Like the new-style MultiFlex board, the old-
style MultiFlex board can be connected to any of
the center-tapped transformers mentioned in
Table 2-2
, provided you observe the following
three rules:
Rule 1: Ground the 0V terminal on the old-
style MultiFlex board to an earth ground.
Do not connect the center tap of the trans-
former to the 0V terminal.
Rule 2: Do not power an old-style MultiFlex
non-center-tapped board with a transformer
that is also powering a center-tapped device.
This means you cannot connect an old-style
MultiFlex non-center-tapped board to a trans-
former that is powering a MultiFlex 16, 16AI,
8RO, 4AO, 8DO, or any previous generation
CPC board that uses center-tapped power. Doing
so will destroy the MultiFlex board.
Rule 3: The secondary of the transformer
must not be grounded on any side.
NOTE: 14AWG or larger should be used for
earth ground and the length should be kept
short. Less than six inches is preferred.
Figure 2-5 - Wiring Non-Center-Tapped MultiFlex Boards to
Transformers With a Center Tap
Earth ground.
Use 14 AWG or
larger.
Keep as short
as possible.
Less
than six inches
is preferred.
Figure 2-6 - Non-Center-Tapped Transformer Wiring
