Starting with Qlik Sense June 2017 you can set a RIM node to be a failover candidate for the Central node. That timeout for failover is set automatically to 10 minutes, but you can change that.
Prior to the February 2018 release, defect QLIK-79412 prevented the value to be changed directly in the QMC.
February 2018 and up
In Qlik Sense February 2018 and above, the value can be changed in the Qlik Sense Management Console. See the Qlik Online Help
for more details.
Qlik Sense June 2017
Qlik Sense September 2017
Qlik Sense November 2017
The preferred method, using the QRS (Repository) API: QRS API: Change Central Node Failover Timeout
The open source Qlik CLI cmdlet for PowerShell is an simplified method to execute QRS APIs. Below guide describes how the Central Node failover timeout can be altered through Qlik CLI. See How To Change Qlik Sense Central Node Failover Timeout Through PowerShell
Manual modification of the database
Not recommended. Note that manual modification to the database are not supported by Qlik. Caution is adviced and backups need to be taken before tampering with the database at any time. See Manually Change Central Node Failover Timeout using PgAdmin