Mr. Heater MHU 80 Instrucciones De Uso Y Manual Del Usuario página 10

ignition control board emits radio noise as the sparking process
WARNING
is underway. The level of energy may be sufficient to disturb
Electric shock hazard. Can cause injury or
a logic circuit in a microprocessor controlled thermostat. It is
death. Do not use this heater if any part has
recommended that an isolation relay be used when connecting
been under water. Immediately call a qualified
the unit heaters to a microprocessor controlled thermostat.
service technician to inspect the furnace and
to replace any part of the control system and
Install the thermostat according to instructions provided. Select
any gas control which has been under water.
circuit protection and wire size according to the unit rating plate.
Install a separate disconnect switch (protected by either fuse or
WARNING
circuit breaker) near the unit so that power can be turned off
Danger of explosion. Can cause injury or
for servicing. Connect wiring through knockout on the junction
product or property damage. If over-heating
box located on the side of the unit heater. Refer to heater wiring
occurs or if gas supply fails to shut off, shut
diagram for connection information. Use 18 gauge wire or larger
off the manual gas valve to the appliance
before shutting off electrical supply.
for thermostat connections.
WARNING
Electrically ground unit in accordance with local codes or, in the
absence of local codes, in accordance with the current National
Electric shock hazard. Can cause injury or
Electrical Code (ANSI/NFPA No. 70) in the U.S.A., and in Canada
death. Before attempting to perform any
with the current Canadian Electrical Code, Part 1 CSA C22.1.
service or maintenance, turn the electrical
power to unit OFF at disconnect switch(es).
NOTE Un-insulated ground wires must be wrapped in electrical
Unit may have multiple power supplies.
tape to avoid damage to the electrical system.
WARNING
Make line voltage connections as shown in figure 7. Connect field
wiring as shown on wiring diagram on unit. Also refer to typical
Danger of explosion and fire. Can cause
diagram in this manual. An additional thermostat wire must be
injury or product or property damage. You
run to terminal "G" on heater when continuous blower is desired.
must follow these instructions exactly.
GAS CONNECTION
GAS CONNECTION
When connecting gas supply lines, the length of the piping run
from the meter to must be considered in determining the pipe size
When connecting gas supply, the length of the run from the
to avoid excessive pressure drop. A line pressure of 7" WC (178mm
meter must be considered in determining the pipe size to avoid
WC) for natural gas should be maintained when sizing the piping.
excessive pressure drop. A line pressure of 7" w.c. (178mm w.c.)
A line pressure of 13" WC (330mm WC) should be maintained
for natural gas should be maintained when sizing piping. A line
for propane (LP) gas. For correct sizing of piping, refer to the
pressure of 13" w.c. (330mm w.c.) should be maintained for
(American) National Fuel Gas Code ANSI Z223.1, or (Canada) CSA
liquefied petroleum (LP) gas. For correct sizing of piping, refer to
B149.1, National Gas and Propane Installation Code or consult the
the (American) National Fuel Gas Code ANSI Z223.1 or (Canada)
utility having jurisdiction.
CSA B149.1, Natural Gas and Propane Installation Code or consult
the utility having jurisdiction. WARNING: TO PREVENT HEATER DAMAGE.
WHEN USING A PROPANE TANK TO SUPPLY
A drip leg should be installed in the vertical pipe run to the unit.
HEATER, A MINIMUM 11"W.C. LOW PRESSURE
In some localities, codes may require that a manual main shutoff
REGULATOR TO A MAXIMUM 14"W.C. LOW PRESSURE
valve and union (furnished by installer) be installed external to the
REGULATOR IS REQUIRED. THIS REGULATOR MUST BE
unit. Union must be of the ground joint type. A drip leg should be
INSTALLED BETWEEN THE TANK AND THE HEATER.
readily accessible to permit cleaning and emptying. See figure 8.
Regulator not supplied with heater.
NOTE If a switch box is mounted over electrical knockouts on
A drip leg should be installed in the vertical pipe run to the unit.
back of unit, leave a minimum of 4" (102mm) clearance between
In some localities, codes may require that a manual main shutoff
switch box and drip leg.
valve and union (furnished by installer) be installed external to the
unit. Union must be of the ground joint type. A drip leg should be
A 1/8" NPT plugged tap shall be installed immediately upstream
readily accessible to permit cleaning and empting. See figure 8.
of the gas supply connection to the heater.
NOTE If a switch box is mounted over electrical knockouts on back
NOTE Compounds used on threaded joints of gas piping must be
of unit, leave a minimum of 4" (102mm) clearance between switch
resistant to the actions of liquefied petroleum gases.
box and drip leg.
A 1/8" NPT plugged tap shall be installed immediately upstream of
the gas supply connection to the heater.
NOTE Compounds used on threaded joints or gas piping must be
resistant to the actions of Liquefied petroleum gasses.
LEAK CHECK
After gas piping is completed, carefully check all piping
connections, (field and factory), for gas leaks. Use a soap solution
or other preferred means.
Due to the natural heating cycles and vibration of this unit it is
recommended, as part of its annual maintenance, to check these
E-10
Compact Unit / Utility Heater
connections for proper tightness and leak-check with a soap
solution or other preferred means prior to putting into service.
CAUTION DO NOT use matches, candles, flame or other sources
of ignition to check for gas leaks.
IMPORTANT The heater and its individual shut off valve must
be disconnected from the gas supply piping system during any
pressure testing of that system at test pressures in excess of 1/2
psig (3.45kPa).
The appliance must be isolated from the gas supply piping system
by closing its individual manual gas shutoff valve during any
pressure testing of the gas supply system at test pressures equal
to or less than 1/2 psig (3.45kPa). See figure 9.
NOTE In case emergency shutdown is required, shut down main
gas valve and disconnect main power to unit. These devices
should be properly labeled by the installer.
START – UP AND OPERATION
UNIT START–UP
FOR YOUR SAFETY READ BEFORE LIGHTING
BEFORE LIGHTING smell all around the appliance area for gas.
Be sure to smell next to the floor because some gas is heavier
than air and will settle on the floor.
Use only your hand to move the gas control switch to the on
position. Never use tools. Do not use excessive force to switch
valve from off to on position. Force or attempted repair may result
in a fire or explosion.
MHU 50/80 unit heaters are equipped with an automatic spark
ignition system. There is no pilot. In case of a safety shutdown,
move thermostat switch to OFF, then return the thermostat switch
to HEAT position.
Should overheating occur, or the gas supply fail to shut off, shut
off the manual gas valve to the appliance before shutting off the
electrical supply.
GAS VALVE OPERATION FOR HONEYWELL
VR8205M SERIES VALVE (FIGURE 10)
1. STOP! Read the safety information at the beginning of this
section.
2. Set the thermostat to lowest setting.
3. Turn off all electrical power to appliance.
4. This appliance is equipped with an ignition device which
automatically lights burner. DO NOT attempt to light the
burners manually.
5. There is a black rotary switch knob that can be moved
between the on and off position. Rotate the switch knob to
the off position. (See Figure 10)
6. Wait five minutes to clear out any gas. If you then smell gas,
STOP! Immediately call your gas supplier from a neighbor's
phone. Follow the gas supplier's instructions. If you do not
smell gas go to next step.
7. Rotate the black switch knob to ON.
8. Turn on electrical power to unit.
9. Set the thermostat to desired setting.
10. The combustion air blower will start. The burners will light
within 40 seconds.
Operating Instructions and Owner's Manual