46
47
Caution
Consult qualified electrician for the electrical
work.
Do not turn on the power until the electrical wiring is finished.
Otherwise, electric shocks or damage to the equipment will occur.
9.
Electric wiring
The power for the water heater is at 120V AC
and 60Hz.
Check the power consumption indicated on the
label, and use an appropriate circuit.
Do not do connect the power supply when not in
use. When the power is off, the freeze preven-
tion heater in the water heater will not activate,
resulting possible damage from freezing.
Do not let the power cord contact the gas piping.
Tie the redundant power cord outside the
water heater. Do not put the extra length in
the equipment. It may cause a fault in the
water heater.
Ground
To prevent an electric shock, provide a ground
with resistance less than 100
Ω
. An electrical en-
gineer should do the work.
The ground terminal is provided at the bottom
of the water heater and explicitly indicated.
Do not connect the ground to the city water
or gas piping. Do not tie the ground to a tele-
phone line.
Installation of breaker
Mount a device which shuts off the electrical path
automatically (leakage breaker) when leakage
from electric facilities is detected (based on tech-
nical criteria).
This appliance must be electrically grounded in accordance with local codes, or in the absence of local
codes, with the National Electrical Code, ANSI/NFPA 70. In Canada, the latest CSA C22.1 Electrical Code.
Caution:
Label all wires prior to disconnection when servicing controls. Wiring errors can cause
improper and dangerous operation.
Verify proper operation after servicing.
Field wiring to be performed at time of appliance installation.
Rainproof
socket
Ground terminal
Ground connection screw
Water
heater
Ground line
Ground line
Ground
Ground connection screw
Water
heater
Maintenance
The venting system must be examined periodically by a qualified service technician to check for any
leaks or corrosion.
The burner flame must be checked periodically for a proper blue color and consistency.
If the flame does not appear normal, the burner may need to be cleaned.
If the burner needs to be cleaned, it must be performed by a qualified service technician.
Do not obstruct the flow of combustion and ventilation air.
The pressure relief valve must be operated once a year to ensure that it is functioning properly and
there is no obstruction. Turn the power off to the unit before opening the relief valve, and make sure
that water draining out of the valve will not cause any damage.
If the relief valve discharges periodically, it may be due to thermal expansion in a closed water system.
Contact the water supplier or a local plumbing inspector on how to correct this situation. Do not plug the
relief valve. See Operation Manual for further maintenance.
Warning: There is a scald potential if the output temperature is set too high.
Should overheating occur, or the gas supply fail to shut off, turn off the manual gas control valve to the appliance.
Do not use this appliance if any part has been under water. Immediately call a qualified service
technician to inspect the appliance and to replace any part of the control system and any gas control
which has been under water.
8.
Supply water and hot water piping
This appliance suitable for potable water and space heating applications. Do not use this appliance if
any part has been underwater. Immediately call a qualified service technician to inspect the appliance
and to replace any part of the control system and gas control which has been under water.
If the water heater is installed in a closed water supply system, such as one having a backflow
preventer in the cold water supply line, means shall be provided to control thermal expansion. Contact
the water supplier or a local plumbing inspector on how to control this situation.
A pressure relief valve must be installed near the hot water outlet that is rated in accordance with and
complying with either The Standard for Relief Valves and Automatic Shutoff Devices for Hot Water
Supply Systems, ANSI Z21.22, or The ANSI/ASME Boiler and Pressure Vessel Code, Section IV
(“Heating Boilers”). This pressure relief valve must be capable of an hourly Btu rated temperature
steam discharge of 399,000 Btuh. Multiple valves may be used. The pressure relief capacity must not
exceed 150 psig. No valve shall be placed between the relief valve and the water heater. The relief
valve must be installed such that the discharge will be conducted to a suitable place for disposal when
relief occurs. No reducing coupling or other restriction may be installed in the discharge line. The
discharge line must be installed to allow complete drainage of both the valve and the line. If this unit is
installed with a separate storage vessel, the separate vessel must have its own temperature and
pressure relief valve. This valve must also comply with The Standard for Relief Valves and Automatic
Gas Shutoff Devices for Hot Water Supply Systems, ANSI Z21.22. (in the U.S. only). A temperature
relief valve is not required, but if one is used, do not install the valve with the probe directly in the flow
of water. This may cause unwarranted discharge of the valve.
Piping and components connected to the water heater shall be suitable for use with potable water.
Toxic chemicals, such as those used for boiler treatment, shall not be introduced into the potable water.
A water heater used to supply potable water may not be connected to any heating system or compo-
nents previously used with a nonpotable water heating appliance.
When water is required in one part of the system at a higher temperature than in the rest of the sys-
tem, means such as a mixing valve shall be installed to temper the water to reduce the scald hazard.
Pass water through the pipe to clean out metal powder, sand and dust before connecting it.
Take appropriate heat insulation measures (e.g., wrapping with heat insulation materials, using elec-
tric heaters) according to the climate of the region to prevent the pipe from freezing.
Use a union coupling or flexible pipe for connecting the pipes to reduce the force applied to the piping.
Do not use piping with a diameter smaller than the coupling.
When feed water pressure is too high, insert a depressurizing valve, or take water hammer preven-
tion measure.
Avoid using joints as much as possible to keep the piping simple.
Avoid piping in which an air holdup can occur.
* Use approved piping materials.
Supply water piping
Do not use PVC piping with city water.
Mount a check valve and a shut off valve (near
the inlet).
In order for the client to use the water heater
comfortably, 98.1 to 491 kPa (14 to 70 PSI) of
pressure is needed for water feeding.
Be sure to check the water pressure. If the
water pressure is low, the water heater cannot
perform to its full capability, and may become
a source of trouble for the client.
Drain piping
Expansion water may drop from the pressure
prevention device and wet the floor. If neces-
sary, provide drain piping or use a drain hose
to remove the water.
Hot water piping
Do not use lead or PVC piping with city water.
The longer the piping, the greater the heat loss.
Try to make the piping as short as possible.
Use a mixing valve with a low water resistance.
Use a shower head with low pressure loss.
If necessary, use a pump or other means to en-
sure that the supply water pressure to the inlet
of the heater does not fall below 200 kPa when
the maximum amount of water is being de-
manded. Also install a pressure meter on the
inlet. If this is not done, local boiling will occur
inside the water heater causing abnormal
sounds and decreasing the durability of the heat
exchanger.
Ask a qualified plumber in the
region for piping and observe
plumbing codes.
Summary of Contents for N-063
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