CK721-A
last module
EOL switch
on (up)
EOL switch
on (up)
CK721-A
last module
EOL switch
on (up)
EOL switch
on (up)
EOL switch
off (down)
first module
CK721-A and S300-DIN Enclosures CK721-A Installation and Operation
2-4 24-10349-8 Rev. B
This document contains confidential and proprietary information of Johnson Controls, Inc.
© 2012 Johnson Controls, Inc.
Lithium Battery
The CK721-A contains a lithium battery that is used for realtime clock backup. The
lithium battery is shipped from the factory charged and operational.
If there are no power outages, the battery should be changed every five years. If a
power outage occurs, the battery life is approximately 30 days. Replace with
Panasonic part number CR2025 or equivalent.
IMPORTANT
Before you replace the lithium battery (recommended every five years or
after extended use), ensure AC power or backup battery power is supplied
to the CK721. If AC power or backup battery power is not supplied before
you remove the lithium battery, the realtime clock will be incorrect.