Bradford-White Corp M-2-50T6DS service manual Sequence of Operation

SEQUENCE OF OPERATION

Residential and light duty commercial electric water heaters are designed to operate using several different operating modes. The common modes and sequence of operation are as follows:

1.Single Element Operation.

2.Double Element Non-Simultaneous Operation (single phase).

3.Double Element Non-Simultaneous Operation (3 phase).

4.Double Element Simultaneous Operation (single phase).

5.Double Element Simultaneous Operation (3 phase).

Sequence of Operation- Single Element Operation.

1Line voltage is applied across terminals L1 &L3 of the thermostat. ECO is closed, so there is voltage at terminal L4 and to one side of the element.

2Tank is cold therefore thermostat

is closed at terminal T2 (calling for heat). This completes the circuit and allows current to flow through the element.

1

ECO

Closed

2

Thermostat closed

at terminal T2

3When the thermostat is satisfied, it opens at terminal T2 interrupting current flow through the element. System is now in stand-by mode, waiting for the next call for heat.

3

Thermostat opens

at terminal T2

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