Frequently Asked Question
A proper procedure to use MBS requires first switching the UPS to the electronic bypass and then applying the manual one. Otherwise you can bypass the input to the output of the UPS and cause a damage. Built-in MBS would be usually protected by additional sensor, so as soon as you open the MBS cover it would switch to an internal bypass.
The "Control Output Signal Port" is a dry-in contact for the MBS. This contact is NO (normally open) and should be connected to External MBS lock/cover. Once the lock is opened it should provide short (close) signal to the connector and it will trigger bypass mode in the UPS. The UPS will not allow switching to line mode until the lock is not locked and the signal is back open.