Schweitzer Engineering Laboratories SEL-352-1 - GRO (Setting Group); HEA (Resistor Heat Report)

Date Code 20010731 Serial Port Communications and Commands 8-21
SEL-352-1, -2 Instruction Manual
GRO (Setting Group)
Access Level 1 and 2
The GROUP command displays or designates the setting group variable. This variable (1–3)
specifies which setting group is the active group when the setting group selection inputs (SS1,
SS2) are not assigned or are deasserted. The following example verifies the existing group
variable, changes it, and then waits for the automatic message when the setting group changes.
The variable must be changed for a certain number of seconds as specified by the SET G setting
TGR before the new settings are enabled.
=>>GRO<ENTER>
Active Group = 1
Group Variable = 1
=>> GRO 2<ENTER>
Change Group Variable:
Are you sure (Y/N) ? Y<ENTER>
=>>
The GROUP command does not clear the event report buffer. If the active group is changed, the
relay pulses the ALARM output contacts and generates the following automatic message:
EXAMPLE: BUS B, BREAKER 3 Date: 02/01/93 Time: 23:31:17.489
Active Group = 2
Group Variable = 2
=>>
Note: The relay will be disabled momentarily while the group switch takes place.
The GROUP command at Access Level 1 shows the active group but does not allow changes.
Access Level 2 allows the GROUP command to change the group variable.
HEA (Resistor Heat Report)
Access Level 1
The SEL-352 Relay tracks heat of the close and open resistor for each of the three phases. The
HEAT command allows you to examine resistor status, presenting the heat content of each
resistor (with respect to ambient) normalized to the resistor failure threshold, 26CF or 26TF. For
example, if the B-phase open resistor (ORB) contains 1.0 J of internal heat, and the trip failure
threshold (26TF) setting is 2.0 J, the HEAT command displays the ORB resistor heat as 0.50.
The HEAT command report headings use a simple format. ORA heads the A-phase opening
resistor column, CRA the A-phase closing resistor column, and so on, for the B- and C-phases.
Automatically repeat the HEAT command by adding a repeat count. To repeat the command
1000 times, type HEA 1000 <ENTER>. The command <CTRL>X cancels the listing at any
time. Repetition is especially useful when testing thermal elements.