Basler Electric BE1-87T - Manual (Page 123)

9171300990 Rev V BE1-87T Difference Data 6-1
SECTION 6 • DIFFERENCE DATA
General
This section provides the information necessary to support BE1-87T, Transformer Differential Relays, with
sensing input type F (three-phases, three inputs each phase). Sensing input type F relays have a style
number with the first character F (refer to Style Number Identification Chart, Figure 6-1). Sensing input
type F relays require the lower connection plug to be removed before the upper connection plug. This
procedure prevents false trips. During installation, the lower connection plug should be installed last.
Differences
Revision P to BE1-87T relays made sensing input type F obsolete and created sensing input type G, for
three-phase, three inputs for each phase. Primary differences between sensing input types F and G are:
• Sensing input type G relays do not require a specific procedure for removing and installing
connection plugs.
• Sensing input type F relays have the normally closed power supply status (PSS) output at terminals
19 and 20 and have shorting bars across the PSS terminals (refer to Figure 6-2).
• Sensing input type F relays have terminal 9 for the common terminal on restrained and unrestrained
outputs.
• Sensing input type G relays have the normally closed PSS output at terminals 9 and 19 and have
NO shorting bars across the PSS terminals (refer to Figure 4-7).
• Sensing input type G relays have terminal 20 for the common terminal on restrained and
unrestrained outputs.
Compatibility
Revision P relays with sensing input type G are NOT compatible with previous versions of the relays with
sensing input type F.
Connections
Sensing input type F relays (three-phase, three inputs per phase) provide protection for transformers
requiring three differential inputs per phase. Be sure to check the model and style number against the
options listed in the Style Number Identification Chart before connecting and energizing a particular relay.
NOTE
Be sure the relay case is hard-wired to earth ground with no smaller than 12
AWG copper wire attached to the ground terminal on the rear of the relay
case. When the relay is configured with other protective devices, it is
recommended to use a separate lead to the ground bus for each relay.
Connections should be made with 14 AWG stranded wire or better except as noted for the ground wire.
Figure 6-3 shows case terminal designations for sensing input type F relays. And Figure 6-4 shows the
test setup. Refer to the test procedures in Section 4 for testing sensing input type F relays. Testing
procedures are the same with the exception of terminal connections and the procedures for removing
connection plugs.