Basler Electric BE1-87T - Manual (Page 38)

3-4 BE1-87T Functional Description 9171300990 Rev V
Auxiliary Relay Option
Auxiliary relays (Option 3-1, 3-2 or 3-5 in the tenth position of the Style Number) are accompanied by two
switches, S1 and S2, which allow the relays to respond to a restrained trip (S1 ON) or to an unrestrained
trip ( S2 ON), or both (S1 and S2 ON). These switches (letter I of Figure 2-4 and described in Table 2-1)
are located on the mother board and are shipped in the ON position. Auxiliary relays may be disabled by
opening both switches ( S1 and S2 OFF).
Power Supply
Relay operating power is developed by a wide-range, isolated, low-burden, switching power supply that
delivers ±12 Vdc to the relay’s internal circuitry. The power supply is not sensitive to the input power
polarity. A front panel LED power indicator lights to indicate that the power supply is functioning properly.
Style number designations and input voltage ranges for the available power supply models are provided
in Section 1, General Information.
Power Supply Status Output (Optional)
The Power Supply Status output relay has normally closed (NC) contacts. The relay is energized by the
presence of nominal voltage at the output of the power supply. Normal operating voltage then keeps the
relay continuously energized and its contacts open. However, if the power supply voltage falls below
requirements, the Power Supply Status output relay will de-energize and close the contacts.
The Power Supply Status output is not associated with any magnetically latched target. The
POWER LED
on the front panel provides a visual indication of the normal operating status of the power supply.
NOTE
Sensing Input Types A through E (first position of the Style Number) have
paddle-operated shorting bars included in the relay case (terminals 19 and 20)
so that the Power Supply Status output terminals can provide a remote
indication that the BE1-87T has been withdrawn from its case or that it has
been taken out of service by removing the connection plugs. Sensing Input
Type G relays do NOT have shorting bars on the Power Supply Status output.
Sensing Input Type G units use terminal 9 (lower terminal block) and terminal
19 (upper terminal block) for the Power Supply Status output.
Target Indicators (Optional)
When the Target option is specified as either C or D, shown in the seventh position of the Style Number,
electronically latched indicators, labeled FUNCTION, are incorporated in the front panel. The
electronically latched and reset targets consist of red LED indicators. The appropriate target is tripped
when either a restrained ( R) or unrestrained (U) output occurs. Latched targets are reset by operating the
target reset switch on the front panel. If relay operating power is lost, any illuminated (latched) targets are
extinguished. When relay operating power is restored, the previously latched targets are restored to their
latched state.
When targets are specified for three-phase relays, three additional
ELEMENT targets are incorporated to
indicate the phase involved. Only the FUNCTION targets, restrained (R) or unrestrained (U) are available
for single-phase units.
Relays can be equipped with either internally operated targets (Type C) or current operated targets (Type
D). Both target types are reset by operating the target reset switch.
• Type C target (referred to as internally operated) is actuated by an integral driver circuit that
responds directly to the relay internal logic. This type of target is tripped regardless of the amount
of current flowing through the associated output contact.
• Type D target (referred to as current operated) is actuated when a minimum of 0.2 A flows
through the associated output contacts. To accomplish this, a special reed relay is placed in
series with the contact to signal the target indicator. (The series impedance of the reed relay is
less than 0.1 ohm.) Current in the output circuit must be limited to 30 amperes for 0.2 seconds, 7
amperes for 2 minutes and 3 amperes continuously.