9328900990 Rev L BE1-951 Input and Output Functions 3-9
0.200
Sec
0
Sec
OR
ONE SHOT
TIMER
AND
OUT[A]
HARDWARE
OUTPUT
OUTPUT
STATUS
AND
AND
OR
Control Override (0/1)
Override State (0/1)
Hold State (0/1)
VO[A]
VIRTUAL OUTPUT
CONTROLLED BY SL-VO[n]
LOGIC EQUATION
HOLD ENA
(SG-HOLD COMMAND)
OUTPUT CONTROL
(CO-OUT COMMAND)
ALMREL
D2647-19
03-13-06
NOT
Figure 3-6. Output Logic, Fail-Safe Alarm Output Contact
Retrieving Output Status
Output status is determined through BESTCOMS by selecting Metering from the R
eports pull-down menu
and selecting the Start Polling button in the lower right hand corner of the screen. Alternately, status can
be determined through the HMI Screen 1.5.2 and through the communication ports using the RG-STAT
(report general-status) command. See Section 6, Reporting and Alarm Functions, General Status
Reporting, for more information.
Relay Trouble Alarm Disable
When the BE1-951 self-diagnostics function detects a relay problem, an internal alarm condition
(ALMREL) is set. This alarm condition disables the outputs and de-energizes the OUTA relay,
closing/opening (depending on style number) the OUTA contact. For more details about this function see
Section 6, Reporting and Alarm Functions, Alarms Function.
Programmable Hold Timer
Historically, electromechanical relays have provided trip contact seal-in circuits. These seal-in circuits
consisted of a dc coil in series with the relay trip contact and a seal-in contact in parallel with the trip
contact. The seal-in feature serves several purposes for electromechanical relays. One purpose is to
provide mechanical energy to drop the target. A second purpose is to carry the dc tripping current from
the induction disk contact, which may not have significant closing torque for a low resistance connection.
A third purpose is to prevent the relay contact from dropping out until the current has been interrupted by
the 52a contacts in series with the trip coil. If the tripping contact opens before the dc current is
interrupted, the contact may be damaged. Of the three items, only item three is an issue for electronic
relays like the BE1-951.
To prevent the output relay contacts from opening prematurely, a hold timer can hold the output contact
closed for a minimum of 200 milliseconds. If seal-in logic with feedback from the breaker position logic is
desired, the BESTlogic expression for the tripping output can be modified. This process is described in
Section 7, BESTlogic Programmable Logic, BESTlogic Application Tips.
The hold timer can be enabled for each input using the SG-HOLD (setting general-hold) command. Hold
timer settings are shown in
Table 3-4.
To enable the hold timer using BESTCOMS, select Inputs and Outputs from the S
creens menu and select
the Outputs 1 – 5, A tab. To enable the hold timer for a desired output, check the box labeled Hold
Attribute by clicking in the box with the mouse pointer. Refer to
Figure 3-7.
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