ABB RER620, Technical Manual

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Section 9
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426 RER620
Technical Manual
Table 383: Tolerances for AC supply power
Table 384: Tolerances for DC supply power
9.1.3 Input Power Measurement
The UPS can measure the input voltage if powered by AC. This measurement is
accomplished with a capacitor voltage divided (CVD) network.
In pole-mounted applications, the control power is always AC. No UPS internal decisions
are made based on the CVD measurement. (The loss-of-control-power alarm is based off
the 60 Vdc rail inside the UPS, not the CVD measurement.) The CVD measurement is
simply reported back to the RER620, which can report it to central control.
The AC power source in almost all systems has one of its two leads referenced to earth
ground. The AC voltage lead that is not referenced to ground is referred to as the Hot lead,
or L1. The lead that is referenced to earth ground is referred to as Neutral, or L2. The UPS
is expecting a power source that has L2 connected to earth ground, and that lead is to be
connected to the UPS L2 connection point.
The UPS AC voltage measurement will draw attention to an incorrectly wired recloser, but
there are exceptions. Present AC control power is derived from a residential transformer
or a single bushing PT. These power sources have the L2 and earth ground connection at
the same potential. It is possible to power an RER recloser from a dual bushing PT where
the AC is “floating.” There may even be parts of the world that supplies residents with
floating AC. In such a situation, the RER620 will report the voltage off by a significant
amount from the actual voltage. The RER620 has an input power calibration function that
may be used to correct the voltage measurement in cases where there is no connection
between L2 and earth ground, or to increase the accuracy of the measurement.
9.1.3.1 Loss of UPS input power alarm.
The UPS is equipped with a form-C dry contacts that will provide an alarm in the event of
power loss. The alarm contacts are energized if input power is present (AC or DC) to the
UPS or if the 60 Vdc rail within the UPS is above 57 Vdc. When input power is present,
pins 2 and 3 of connector W2 are connected. When there is insufficient power, pins 1 and
2 are connected.
In addition, the Loss of input power alarm is also transmitted to the RER620 via the RS485
communication link.
UPS Voltage Class
Minimal V ON for
Rising AC
Minimal V OFF for
Falling AC
Maximum V OFF
for Rising AC
Maximum V ON for
Falling AC
120vac (ANSI) 70 to 82 AC 80 to 68 AC 150 to 170 AC 155 to 136 AC
240vac (EU) 134 to 145 AC 140 to 130 AC 264 to 294 AC 288 to 268 AC
UPS Voltage Class
Minimal V ON for
Rising DC
Minimal V OFF for
Falling DC
Maximum V OFF
for Rising DC
Maximum V ON for
Falling DC
120vac (ANSI) 93 to 104 Vdc 91 to 80 Vdc 183 to 205 Vdc 200 to 185 Vdc
240vac (EU) 178 to 203 Vdc 168 to 187 Vdc 360 to 400 Vdc 400 to 365 Vdc