John Wood Commercial Electric Water Heater - Manual (Page 8)

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the water heater. If the heater is located a long distance
away from the electrical supply, the wire size of the branch
circuit should be increased. The voltage measured at the
heater should not be less than 3% lower than what is meas-
ured at the supply. If your calculated value does not appear
in the table, substitute the next highest rating listed in the
table.
1. Ensure the element marking and rating plate data corre-
spond with the electric service available.
2. Install a branch circuit directly from the main service
panel to the water heater. The wiring of this circuit must
be of adequate size for the length of run and the load
(see Table 3).
3. A ground wire must run from the green ground screw
provided at the electrical connection point in the heater
junction box to the ground connection at the service
panel.
4. Final connections are made in the control panel box on
the heater.
5. The heater you have received is internally wired. A spe-
cific wiring diagram for each heater is located inside the
control panel. All internal wiring is colour-coded and con-
nections must be made as shown in the wiring diagrams
(Figures 5-10 for Canada, Figures 11-16 for USA).
Fuses
Components in the power circuit are protected by fuses. For
voltage supplies up to 480V, the fuses are rated for 30
amperes, class G. For voltage supplies of 600V, the fuses
are rated for 15 amperes, class G. Replace fuses with same
size, type and rating only.
Note: These fuses are not required or installed in water
heaters sold in Canada.
Phase Conversion (USA only)
To Single Phase
If the heater is shipped for connection to a three-phase elec-
trical service, it may be connected to a single-phase electri-
cal service of the same voltage by making the following
changes:
1. Disconnect all the blue wires and all the yellow wires
from Terminal Block L3.
2. Reconnect all the blue wires to Terminal Block L1 (with
the black wires).
3. Reconnect all the yellow wires to Terminal Block L2 (with
the red wires).
4. Connect incoming power to Terminal Blocks L1 and L2.
To Three Phase
If the heater is shipped for connection to a single-phase
electrical service it may be connected to a three-phase elec-
trical service of the same voltage by making these changes:
1. Disconnect all the blue wires from Terminal Block L1.
2. Disconnect all the yellow wires from Terminal Block L2.
3. Reconnect the blue wires and the yellow wires to
Terminal Block L3.
4. Connect incoming power to Terminal Blocks L1, L2, and
L3.
Installation Check List
Check Here
1. Are the fuse and wire sizes correct?
2. Is the certified relief valve installed?
3. Were steps taken to prevent water damage in
case of leaks?
4. Has the relief valve been piped to a suitable
drain point?
5. Is the relief valve discharge unobstructed?
6. Is the heater completely filled with water?
7. Is the cold water supply valve open?
If the answer to the above are yes, turn on the
power and enjoy all the hot water you need, all the
time.