Elgar CW 1251M, Operation Manual

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Elgar CW-M Series
21
3.7 Sense Connections
The CW Series unit can be used with or without remote sense leads connected to the
load. Where the sense leads (line and neutral sense) are connected determines the
point at which the CW output voltage will be precisely regulated.
As shipped, the units are configured for local sense operation. This is achieved by
connecting shorting jumpers between the sense and AC output terminals of the rear
panel output terminal block, as shown in Figure 3–8.
When using remote sensing, the shorting jumpers must be removed, and the remote
sense leads connected from the CW sense terminals to the load. The point of voltage
regulation will now be at the load, and any voltage drop across the interconnecting
output cable will be compensated.
In the event that the external remote sense circuit opens, the CW maintains control of
the output voltage by utilizing a redundant sense circuit. This redundant circuit is
comprised of 10k
Ω resistors internally connected from the AC output terminals to the
voltage control circuitry. However, since the unit is calibrated with the sense leads
connected, this mode of operation will incur reduced accuracy in the AC output voltage
because of the presence of the 10k
Ω resistors.
Figure 3–8 Output Voltage Sensing Configuration