Unit Part (Catalog) & Serial Numbers; Memory Protection - Lennox ComfortSense 7500 Commercial Installation And Setup Manual

Unit Part (Catalog) & Serial Numbers
A label on the back of the thermostat is visible
through an opening in the back of base plate. This
identifies the Lennox Catalog Number, Part Number
and Serial Number. Separate the base plate from
the thermostat to see additional manufacturing
information.

Memory Protection

The thermostat stores all the information concerning
its programming (state, mode, program information,
last temperature measured) in a nonvolatile
memory.
This function avoids the loss of the state of the
thermostat when a power-down occurs. The only
thing that might be lost is the clock and date
information, however, a super capacitor will
remember clock / date information for as long as it
has a charge (approximately 24 hours). When
power down occurs (due to a power outage) the
thermostat is able to shut off heat relays (Y1, Y2,
W1, W2) when in heating mode and W1 and W2
when in cooling mode. The O and B relay will
maintain their last state. When power is restored the
thermostat will be in heat /cool mode so either mode
can run to re-satisfy the temperature setting. Day
and time (schedules) may be off due to battery loss
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