Basler Electric BE1-700 - Manual (Page 48)

Figure 3-6. Output Logic, Fail-Safe Alarm Output Contact
Retrieving Output Status
Output status is determined through BESTCOMS by selecting Metering from the Reports pull-down menu
and selecting the Start Polling button on 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 BE1-700 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 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 BE1-700.
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 8, Application, Application Tips, Output Contact Seal-In.
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 Screens 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.
0.200
Sec
0
Sec
O
R
ONE SHOT
TIMER
AND OUT[A]
HARDWARE
OUTPUT
OUTPUT
STATUS
AND
AND
O
R
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 P0055-47
NOT
3-8 BE1-700 Input and Output Functions 9376700990 Rev M