Moyer Diebel 501HT - Manual (Page 15)

5
Installation
Booster Heater/Wash Tank Heater Interlock Circuit
For Model 201HT, 401HT, 501HT dishwashers beginning with S/N 14236 and above.
The booster heater/wash tank heater interlock circuit removes power from the wash tank heater whenever
the booster heater contactor energizes. The illustration below shows how the booster heater contactor is
wired. The booster heater contactor is located behind the lower front access panel.
Interlock Circuit Operation
1. The dishwasher fills with water when the
main power switch on the dishwasher is turned on.
The booster heater thermostat calls for heat
which energizes the booster heater contactor.
2. The auxiliary contact on the top of the contactor
opens and removes power from the wash tank
heater.
3. When the booster heater thermostat is
satisfied, the booster heater contactor de-
energizes and the auxiliary contacts close
applying power to the wash tank heater.
4. This operation is repeated whenever the
booster thermostat calls for heat.
To booster
heater contactor
1PH
208-230VAC
To
Auxiliary
Contactor
115VAC
No power when booster
heater is connected for 1 PH
No power when booster
heater is connected for 1 PH
L1 L2 L3 N
Main Terminal Block (MTB)
Booster Heater Element
Field Conversion from Single to Three Phase Operation
(continued)
ATTENTION ELECTRICIAN:
The Main Terminal Block (MTB) is a 4-wire
connection block which includes a current-carrying
neutral. The block can be connected for 3PH or 1PH
depending on how the booster heater is wired (
see the previous page). Refer to the diagram to the
right and connect the main incoming electric service
accordingly. The data plate on the lower front
cover of the dishwasher provides the correct power
requirements.
Contact the local authorized service agent if there
are any questions concerning the proper power
connections.
To wash
tank heater
115VAC
From
main
terminal block
115 VAC
From
main
terminal block
1 PH
208-230VAC
No power
when booster
heater is
connected for
1 PH
No power when booster
heater is connected for 1 PH
L1
L3
L1
N
L2
To booster heater
1 PH 208-230VAC 1H2
1H3
1H1
Auxiliary
Contactor
Booster Heater
Contactor