Wire Types And Maximum Distances - Emerson 818-9010 Installation And Operation Manual

Neither side of the secondary should be connected
to ground. Also, do not connect the center tap (if pro-
vided on the transformer) to ground. The entire sec-
ondary of the transformer should be isolated from any
ground.
Figure 2-5 - Non-Center Tapped Transformer Wiring
2.4.2. Wire Types and Maximum
Distances
For powering I/O boards, use only the listed wire
types in . Two-conductor non-shielded
Table 2-10
cables are the recommended wire for connecting the
transformer to the High Pressure CO2 controller.
Shielded cable should not be used for power wiring.
The center tap should be left disconnected if present
on the transformer.
Power Wiring Types
14 AWG
18 AWG
Table 2-10
- Power Wiring Types
The wire length from the transformer determines
the type wire gauge used. In most cases, the distance
between the High Pressure CO2 controller and the
transformer that supplies power to it is not enough to
be of concern; however, it is very important NOT to
exceed this maximum wire length or the controller
will not operate correctly.
Use these formulas to determine if the wire gauge
you are using fits within specification:
14 AWG:
Feet = 1920/VA
18 AWG:
Feet = 739/VA
(VA is the total VA rating of the controller)
For example, if you had an 80 VA load:
14 AWG: 24 ft.
18 AWG: 9 ft. (rounded down)
Table 2-11
- Power Wire Lengths
Sensors requiring 24VAC should not be powered
from the same transformer that is powering the input
board. Any devices that will be connected to the High
Pressure CO2 controller inputs or outputs must be
powered with a separate 24VAC transformer.
Belden 9495
Belden 9495
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