GAMATRONIC ELECTRONIC INDUSTRIES LTD.
+
SA: 20, 30 and 40 kVA, Release 2.1
17
3. Measure the ac input voltage. Phase-to-phase voltage (measured between L1-L2,
L2-L3, and L3-L1) should be 3x400 Vac ±10 %. Phase-to-neutral voltage (measured
at L1, L2, and L3) should be 230 Vac, ±10 %.
4. Verify that voltage between neutral and ground is between 0 and 2 Vac.
5. Check the dc voltage at the switch of the battery cable and verify that it is +384 V
and –384 V.
6. Verify that appropriate 15 A ac and 20 A dc fuses are present per phase per
module.
7. An external N.O. EPO switch can be connected according to connection schematic
(Figure 82 on page 21). EPO wiring and switch must be rated for at least 1 A / 24
Vdc.
4.3.4 Cabling
4.3.4.1 Neutral Line
During both installation and operation of the Power +, a neutral line must always be
connected to the UPS. This neutral line must be connected at all times while the UPS is
working and should not be disconnected at any time.
Caution: If at any time the neutral line becomes disconnected, there will be no input or
output reference voltage because the input neutral line and the output neutral line are
physically linked together. This may result in the system defining its own reference voltage,
which will be set by the load distribution between the three phases. This can cause serious
damage to the UPS.
Caution: A 4-pole switching system can disconnect the neutral line.
Warning: If you have a four-pole mains-to-generator switching system you are in danger of
having the neutral line disconnected when the four-pole switch is operated. This can result
in the problems described above.
To avoid these problems, we strongly recommend that, if you use a four-pole mains-to-
generator switching system, you install an isolation transformer that constantly provides a
neutral line to the UPS.
Figure 14 shows the wrong way to connect the UPS with a grounded-neutral generator.
Figure 15 shows an acceptable connection solution if you already have a grounded-neutral
generator.
Figure 16 shows the preferred generator (neutralized rather than grounded) and the
preferred connection (three-pole).
To Next Page
Loading...
