Page 41 - GuardII+ Series 4208 Platform PD User Manual

Installation

5.7. Termination Box Check

If the machine is running when the PD card is connected, it is a good idea to use a digital
voltmeter to measure the voltage at each of the connectors on the termination panel.

5.7.1. Termination Check (BUS or PDA)
BUS or PDA termination voltages are quite predictable. The expected ac synchronization
voltage can be calculated based on the line voltage of the machine the sensors are connected
to; common values are shown below:

Line Voltage Expected Termination Voltage
(kV, phase-to- (mVrms)
phase) 50 Hz 60 Hz
3.3 58 ~ 86 69 ~ 103
4.16 74 ~ 110 87 ~ 131
6.6 115 ~ 173 138 ~ 206
11 192 ~ 288 229 ~ 344
13.8 240 ~ 360 288 ~ 432
18 314 ~ 470 376 ~ 564
22 383 ~ 575 459 ~ 689
26 453 ~ 679 543 ~ 815

If the measured voltage is significantly different from the expected voltage or from the
voltages of the other sensors, there may be a problem with the sensor or the ac
synchronization signal may be distorted.

5.7.2. Termination Check (SSC)
The ac voltage produced by an SSC is less predictable than for a BUS or PDA installation.
Each pair of Endwinding and Slot connectors should have the same ac voltage; if not, there
may be a problem with that sensor. However, the output voltages of other SSCs can be
significantly different:

• For example, the AΦ Endwinding and AΦ Slot connectors on the left side of the
termination panel should read the same ac voltage, but that voltage may be quite
different from the voltage read at the AΦ Endwinding and AΦ Slot connectors on the
right side of the termination panel.

The voltage of the external reference output should also be verified as suitable for the
input used; so less than 20 Vac if the Low Voltage external reference is to be used.

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