Legend LB 1000 Installation Operation & Maintenance - High Altitude Installations
5
These are available from the Canadian Standards Association,
8501 East Pleasant Valley Road, Cleveland, OH 44131, USA, or,
Canadian Gas Association Laboratories, 55 Scarsdale Road,
Don Mills, Ontario M3B 2R3, Canada.
GROUNDING INSTRUCTIONS
This boiler must be grounded in accordance with the National
Electrical Code and/or local codes. Boiler is polarity sensitive,
correct wiring is imperative for proper operation.
This boiler must be connected to a grounded metal, permanent
wiring system, or an equipment grounding conductor must be
run with the circuit conductors and connected to the equipment
grounding terminal or lead on the boiler.
INLET WATER CONSIDERATIONS
To minimize the amount of condensate, a minimum inlet water
temperature to the heat exchanger of 140°F (60°C) shall be
maintained. This temperature can be acquired by returning 140°F
(60°C) water from the remote storage tank to the boiler or by
incorporating a by-pass loop between the boiler’s inlet and outlet
connections.
Circulating water through the boiler and to the remote storage
tank (if applicable) is accomplished by a built-in pump on LW
models only. For hot water heating systems using the LB model,
the circulating pump is NOT provided and must be field installed.
CORRECT GAS
MAKE SURE THE GAS ON WHICH THE BOILER WILL OPERATE
IS THE SAME AS THAT SPECIFIED ON THE BOILER RATING
PLATE. DO NOT INSTALL THE BOILER IF EQUIPPED FOR A
DIFFERENT TYPE OF GAS — CONSULT YOUR SUPPLIER.
PRECAUTIONS
IF THE UNIT IS EXPOSED TO THE FOLLOWING, DO NOT OPERATE
UNTIL ALL CORRECTIVE STEPS HAVE BEEN MADE BY A
QUALIFIED SERVICEMAN:
1. EXPOSURE TO FIRE.
2. IF DAMAGED.
3. FIRING WITHOUT WATER.
4. SOOTING.
IF THE BOILER HAS BEEN EXPOSED TO FLOODING, IT MUST BE
REPLACED.
LIQUID PETROLEUM MODELS
Boilers for propane or liquefied petroleum gas (LPG) are different
from natural gas models. A natural gas boiler will not function
safely on LP gas and no attempt should be made to convert a
boiler from natural gas to LP gas.
LP gas must be used with great caution. It is highly explosive
and heavier than air. It collects first in the low areas making its
odor difficult to detect at nose level. If LP gas is present or even
suspected, do not attempt to find the cause yourself. Leave the
building, leaving doors open to ventilate, then call your gas
supplier or service agent. Keep area clear until a service call has
been made.
At times you may not be able to smell an LP gas leak. One cause
is odor fade, which is a loss of the chemical odorant that gives LP
gas its distinctive smell. Another cause can be your physical
condition, such as having a cold or diminishing sense of smell
with age. For these reasons, the use of a propane gas detector
is recommended.
IF YOU EXPERIENCE AN OUT OF GAS SITUATION, DO NOT TRY
TO RELIGHT APPLIANCES YOURSELF. Call your local service
agent. Only trained LP professionals should conduct the required
safety checks in accordance with industry standards.
HIGH ALTITUDE INSTALLATIONS
WARNING
INSTALLATIONS ABOVE 2000 FEET (600 M) REQUIRE
REPLACEMENT OF THE BURNER ORIFICE IN ACCORDANCE
WITH SECTION 8.2.1 OF THE NATIONAL FUEL GAS CODE (ANSI
Z223.1). FAILURE TO REPLACE THE ORIFICE WILL RESULT IN
IMPROPER AND INEFFICIENT OPERATION OF THE APPLIANCE
RESULTING IN THE PRODUCTION OF INCREASED LEVELS OF
CARBON MONOXIDE GAS IN EXCESS OF SAFE LIMITS WHICH
COULD RESULT IN SERIOUS PERSONAL INJURY OR DEATH.
Ratings specified by manufacturers for most appliances apply
for elevations up to 2000 feet (600 m). For elevations above 2000
feet (600 m), ratings must be reduced at the rate of 4% for each
1000 feet (300 m) above sea level. For example, if a boiler is
rated at 500,000 Btu/hr. at sea level, to rate the boiler at 4000 feet
(1200 m), the original rating is reduced by 16 percent (4 x 4%) to
a rating of 420,000 Btu/hr.
The input reduction is primarily achieved by reducing the size of
the main burner orifice. To do this, the main burner orifices require
replacement with an orifice sized for the particular installation
elevation. Part number for gas orifices for altitudes up to 4000
feet (1220 m) are given in Table 5. Orifices for higher altitudes
are special order and may be obtained from A. O. Smith Water
Products Company. When ordering, be sure to state the model
number and the altitude of the location where the boiler is installed.
TABLE 5. LEGEND 2000 ORIFICE TABLE
Natural Gas
Propane
Size
Elevation
Model
Part No.
Part No.
(In.)
(Ft.)
LB/LW-500
*191884-0
—
0.391
0-2000
LB/LW-500
191884-1
—
0.384
2001-3000
LB/LW-500
191884-2
—
0.374
3001-4000
LB/LW-500
—
192741-0
0.229
0-2000
LB/LW-500
--
192741-1
0.226
2001-3000
LB/LW-500
--
192741-2
0.223
3001-4000
LB/LW-750(USA)
*191884-3
--
0.484
0-2000
LB/LW-750(USA)
191884-5
--
0.469
2001-3000
LB/LW-750 USA
191884-7
--
0.461
3001-4000
LB/LW-750 CAN
*191884-11
--
0.464
0-2000
LB/LW-750 CAN
191884-12
--
0.450
2001-3000
LB/LW-750 CAN
191884-13
--
0.443
3001-4000
LB/LW-750
--
192741-3
0.286
0-2000
LB/LW-750
--
192741-4
0.282
2001-3000
LB/LW-750
--
192741-6
0.278
3001-4000
LB/LW-1000
*192222-0
--
0.555
0-2000
LB/LW-1000
192222-1
--
0.537
2001-3000
LB/LW-1000
192222-2
--
0.533
3001-4000
LB/LW-1000
--
*192739-0
0.333
0-2000
LB/LW-1000
--
192739-1
0.329
2001-3000
LB/LW-1000
--
192739-2
0.325
3001-4000
*Factory installed orifice.
Upon completion of derating of the boiler, adjustment to the gas
pressure regulator may be required. See GAS PRESSURE
REGULATORS in this manual for inlet and manifold pressure
requirements.
Also, due to the input rating reduction required at high altitudes,
the output rating of the appliance is also reduced and should be
compensated for in the sizing of the equipment for applications.