GE T35 UR Series, Instruction Manual

Page: 290 / 568

5-168 T35 Transformer Protection System GE Multilin
5.8 INPUTS AND OUTPUTS 5 SETTINGS
5
Since the relay asserts the output contact and reads back its position, it is possible to incorporate self-monitoring capabili-
ties for the latching outputs. If any latching outputs exhibits a discrepancy, the
LATCHING OUTPUT ERROR
self-test error is
declared. The error is signaled by the
LATCHING OUT ERROR
FlexLogic operand, event, and target message.
• OUTPUT H1a OPERATE : This setting specifies a FlexLogic operand to operate the ‘close coil’ of the contact. The
relay will seal-in this input to safely close the contact. Once the contact is closed and the
RESET
input is logic 0 (off),
any activity of the
OPERATE
input, such as subsequent chattering, will not have any effect. With both the
OPERATE
and
RESET
inputs active (logic 1), the response of the latching contact is specified by the
OUTPUT H1A TYPE
setting.
• OUTPUT H1a RESET : This setting specifies a FlexLogic operand to operate the ‘trip coil’ of the contact. The relay will
seal-in this input to safely open the contact. Once the contact is opened and the
OPERATE
input is logic 0 (off), any
activity of the
RESET
input, such as subsequent chattering, will not have any effect. With both the
OPERATE
and
RESET
inputs active (logic 1), the response of the latching contact is specified by the
OUTPUT H1A TYPE
setting.
• OUTPUT H1a TYPE : This setting specifies the contact response under conflicting control inputs; that is, when both the
OPERATE
and
RESET
signals are applied. With both control inputs applied simultaneously, the contact will close if set to
“Operate-dominant” and will open if set to “Reset-dominant”.
Application Example 1:
A latching output contact H1a is to be controlled from two user-programmable pushbuttons (buttons number 1 and 2). The
following settings should be applied.
Program the Latching Outputs by making the following changes in the
SETTINGS

INPUTS/OUTPUTS

CONTACT OUT-
PUTS

CONTACT OUTPUT H1a
menu (assuming an H4L module):
OUTPUT H1a OPERATE:
“
PUSHBUTTON 1 ON
”
OUTPUT H1a RESET:
“
PUSHBUTTON 2 ON
”
Program the pushbuttons by making the following changes in the
PRODUCT SETUP

USER-PROGRAMMABLE PUSHBUT-
TONS

USER PUSHBUTTON 1
and
USER PUSHBUTTON 2
menus:
PUSHBUTTON 1 FUNCTION:
“Self-reset”
PUSHBUTTON 2 FUNCTION:
“Self-reset”
PUSHBTN 1 DROP-OUT TIME:
“0.00 s”
PUSHBTN 2 DROP-OUT TIME:
“0.00 s”
Application Example 2:
A relay, having two latching contacts H1a and H1c, is to be programmed. The H1a contact is to be a Type-a contact, while
the H1c contact is to be a Type-b contact (Type-a means closed after exercising the operate input; Type-b means closed
after exercising the reset input). The relay is to be controlled from virtual outputs: VO1 to operate and VO2 to reset.
Program the Latching Outputs by making the following changes in the
SETTINGS

INPUTS/OUTPUTS

CONTACT OUT-
PUTS

CONTACT OUTPUT H1a
and
CONTACT OUTPUT H1c
menus (assuming an H4L module):
OUTPUT H1a OPERATE:
“VO1”
OUTPUT H1c OPERATE:
“VO2”
OUTPUT H1a RESET:
“VO2”
OUTPUT H1c RESET:
“VO1”
Since the two physical contacts in this example are mechanically separated and have individual control inputs, they will not
operate at exactly the same time. A discrepancy in the range of a fraction of a maximum operating time may occur. There-
fore, a pair of contacts programmed to be a multi-contact relay will not guarantee any specific sequence of operation (such
as make before break). If required, the sequence of operation must be programmed explicitly by delaying some of the con-
trol inputs as shown in the next application example.
Application Example 3:
A make before break functionality must be added to the preceding example. An overlap of 20 ms is required to implement
this functionality as described below: