Basler Electric BE1-851 - Manual (Page 50)

Alternately, status of output contacts can be assessed at HMI Screen 1.5.2 and through the
communication ports using the RG-STAT (report general-status) command. See Section 6, Reporting and
Alarms, General Status Reporting, for more information.
Relay Trouble Alarm Disable
When the BE1-851 self-diagnostics function detects a relay problem, an internal alarm condition is set.
This alarm condition disables the outputs and de-energizes the OUTA relay toggling the OUTA contact.
For more details about this function see Section 6, Reporting and Alarms, 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 BE1-851.
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 output using the SG-HOLD (setting general-hold) command. 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. In Figure 3-8, the Hold Attribute for OUT1, OUT2, and
OUT5 is enabled.
Figure 3-8. Inputs and Outputs Screen, Outputs 1-5 Tab
3-8 BE1-851 Input and Output Functions 9289900990 Rev R