Specifications

PIP ELSAP20 June 2007
Low-Voltage Automatic Transfer Switch
4.4.6 LCD displays shall be provided with “System Status” screens that display
clear descriptions of the active operating sequences and switch positions.
4.4.7 Operational parameters shall be settable either locally or remotely by way of
serial communications.
4.4.8 Voltages and frequencies on both the normal and alternate sources shall be
continuously monitored.
4.4.9 Pickup, dropout, and trip setting capabilities shall be provided in accordance
with Table 1.
Table 1 – Pickup, Dropout, and Trip Settings
Parameter Dropout / Trip Pickup / Reset
Undervoltage 75 to 98% 85 to 100%
Overvoltage 105 to 110% 103 to 105%
Underfrequency 88 to 98% 90 to 100%
Overfrequency 103 to 105% 102 to 104%
Voltage unbalance 5 to 20% 1% below dropout
4.4.10 Unless otherwise specified on the purchaser’s PIP ELSAP20D Data Sheet,
transfer to an alternate power source shall be initiated upon reduction of the
source voltage to 85% of nominal voltage and retransfer to normal shall be
permitted when the source voltage restores to 90% of nominal voltage.
4.4.11 Unless otherwise specified on the purchaser’s PIP ELSAP20D Data Sheet,
the transfer to an alternate power source shall be initiated upon reduction of
the source frequency to 90% and the retransfer to normal shall be permitted
when the source frequency restores to 95%.
4.4.12 An adjustable time delay of 0 to 6 seconds minimum shall be provided to
override momentary normal source outages and delay all transfer and engine
starting signals. The default time delay setting shall be 1 second.
4.4.13 An adjustable time delay of 0 to 5 minutes minimum on transfer to the
alternate power source shall be provided. The time delay shall be initially set
at 0.
4.4.14 Unless otherwise specified on the purchaser’s PIP ELSAP20D Data Sheet,
retransfer to normal source shall be manually performed.
4.4.15 Controllers shall be capable of sensing the phase rotation of both the normal
and emergency sources. A source shall be considered unacceptable if the
phase rotation is not the preferred rotation selected.
4.4.16 Controllers shall be provided with diagnostic screens. The screens shall
provide information on the status of input signals to the controllers that may
prevent load transfer commands from being completed.
4.5 Optional Features
4.5.1 If specified on the purchaser’s PIP ELSAP20D Data Sheet, the following
signal lights shall be provided:
a. Green light to indicate that an automatic transfer switch is connected to
the normal source
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