Sinclair SWH-15/190TL Service Manual page 20

3 Power Supply Wiring .
A. Power Supply Schematic Diagram
Warming:
Although there is a leakage protector in the electric control box of the unit, for the security reason, it is
required that a leakage protection equipped cable and Earthing should be applied for the unit according to
the requirement on the above diagram.
B. Cable Diameter Selection
The power supply wiring refers to the wiring to the main line (a) of junction box and the wiring (b) to the
power supply equipment. Please select the cable diameter according to the following methods
1) Diameter of the main line (a):
Get from the power supply specification table according to the sum of horsepower of the unit.
2) Diameter of the wiring from the junction box to the power supply equipment:
When the water heaters are less than 5 sets, the diameter the wiring from the junction box to the power
supply equipment should be the same as the main line (a); when the water heaters are more than 6 sets, the
power supply equipment should have two sets of electric control box and the diameter should be get from
the power supply specification table according to the sum of horsepower of the units connected by the
electric control box.
Sanitary Water Heater Technical Manual