SEQUENCE OF OPERATION
Sequence of Operation- Double Element, Non-Simultaneous Operation, Single Phase,Off Peak.
Some electric utility companieswill offer discounts for using electricity during“Off Peak” Times of the day. The system
allows the use of an “Off Peak” meter, which interrupts power to the lowerelement during high power demand periods.
Line voltage is appliedacross terminals
L1 & L3 of the upper thermostat. Line voltage from
off peak meter is supplied to terminal L1 of lower
thermostat. ECO in the upper thermostat isclosed,
so there is voltage at terminalL4 of upper
thermostat and to one side of the upper element.
Tank is cold thereforeboth thermostats
are closedat terminal T2 (calling for heat). The
circuit is complete through the upper thermostat
only, allowing current to flow through upper
element.
1
2
When upper thermostat is satisfied, it opens at
terminal T2 interrupting current flow through upper
element, and closes at terminal T4 allowing voltage
to pass to one sideof the lower element. This
completes the circuit throughthe lower thermostat
and off peak meter allowing currentflow through
lower element.
3
When the lower thermostat is satisfied, it opens at
terminal T2 interrupting current flow through lower
element. The system is now in stand-by mode
waiting for the next call for heat
4
During peak power demand periods as determined
by the local utility, the off peak meterwill interrupt
power to terminal L1 of lower thermostat.Only the
top thermostat/element combination is allowed to
operate during this period.
5
ECO
Closed
From
Off Peak
Meter
12
Thermostat closed
at terminal T2
3
Thermostat closed
at terminalT4
From
Off Peak
Meter
45
Thermostat closed
at terminal T2
Thermostat closed
at terminal T2
Thermostat open
at terminal T2
Off Peak
Power interrupted
Thermostat closed
at terminal T2
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