LP-446-r4 Rev. 10.12.16
38
Never use an open flame (match or lighter) to check for gas
leaks. Use a soapy solution to test connection. Failure to use
a soapy solution test or check gas connection for leaks can
result in substantial property damage, severe personal injury,
or death.
Use two wrenches when tightening gas piping at the boiler: One
to prevent the boiler gas line from turning. Failure to prevent
the boiler gas connection from turning could result in damage
to the gas line components, substantial property damage,
severe personal injury, or death.
CSA or UL listed flexible gas connections can be used when
installing the boiler. Flexible gas connections have different
capacities and must be sized correctly for the connected boiler
firing rates. Consult with the flex line supplier to assure the
line size is adequate for the job. Follow local codes for proper
installation and service requirements.
B. Gas Table
Refer to Table 14 to size the supply piping to minimize pressure
drop between the meter or regulator and unit. Maximum
capacity of pipe in cubic feet of gas per hour for gas pressures of
.5 w.c. or less and a pressure drop of .3 inch w.c.
C. Check Inlet Gas Pressure
The gas valve is equipped with an inlet gas pressure tap that can
be used to measure the gas pressure to the unit. To check gas
pressure, perform the steps listed below:
1.
IMPORTANT!
Before you connect to the inlet pressure, shut
off the gas and electrical power to unit.
2. Loosen the pressure tap with a small screwdriver. Refer to
Figures 32 and 33 for location.
3. Each unit is equipped with a needle valve that will accept a
5/16 ID hose to connect to a digital manometer or liquid gauge
to measure incoming pressure from 0-35” w.c.
4. Turn on the gas and power up the unit.
5. Put the unit into manual test mode (details on test mode in
Part 10). In test mode, monitor pressure to assure it does not
drop below 1 inch from its idle reading. If gas pressure is out of
range or pressure drop is excessive, contact the gas utility, gas
supplier, qualified installer, or service agency to determine
correct action that is needed to provide proper gas pressure
to the unit. If Gas Pressure is within normal range proceed to
Step 6.
6. Exit test mode, then turn power off and shut off gas supply
at the manual gas valve before disconnecting the hose from
the gas monitoring device. Tighten screw on the pressure tap
and turn gas on. Check for leaks with soapy solution. Bubbles
will appear on the pipe to indicate a leak is present.
Ensure the pressure tap screw is properly tightened to prevent
gas leaks. Failure to do so could cause substantial property
damage, severe personal injury, or death.
The gas piping must be sized for the proper flow and length
of pipe to avoid pressure drop. The gas meter and regulator
must be properly sized for the total gas load. If you experience
a pressure drop greater than 1” w.c. (.87 kPa), the meter,
regulator or gas line may be undersized or in need of service.
You can attach a manometer to the incoming gas drip leg after
removing the cap. The gas pressure must remain between 3.5”
(.87 kPa) and 14” (3.5 kPa) during stand-by (static) mode and
while in operating (dynamic) mode.
If an in-line regulator is used, it must be a minimum of 10 feet
from the boiler. It is very important that the gas line is properly
purged by the gas supplier or utility. Failure to properly purge
the lines, or improper line sizing, will result in ignition failure.
This problem is especially noticeable in NEW LP installations
and empty tank situations. This situation can also occur when
a utility company shuts off service to an area to provide
maintenance to their lines. This gas valve must not be replaced
with a conventional gas valve under any circumstances.
DO NOT adjust or attempt to measure gas valve outlet
pressure. The gas valve is factory-set for the correct outlet
pressure and requires no field adjustment. Attempts by the
installer to adjust or measure the gas valve outlet pressure
could result in damage to the valve and cause substantial
property damage, severe personal injury, or death.
Natural Gas Supply Piping Capacity Chart
(0.6 Specific gravity gas; 0.5” WC pressure drop)
*Schedule 40 iron pipe size in nominal inches
Cubic Ft. Hr.
500
1000
1500
2000
2500
3000
3500
4000
Model
1 Boiler
2 Boilers
3 Boilers
4 Boilers
5 Boilers
6 Boilers
7 Boilers
8 Boilers
500 @ 100’ of
Pipe
1 1/2”
2”
2 1/2”
3”
3”
3”
4”
4”
500 @ 250’ of
Pipe
2”
2 1/2”
3”
3”
4”
4”
4”
4”
Cubic Ft. Hr.
700/850
1400/1700
2100/2550
2800/3400
3500/4250
4200/5100
4900/5950
5600/6800
Model
1 Boiler
2 Boilers
3 Boilers
4 Boilers
5 Boilers
6 Boilers
7 Boilers
8 Boilers
700/850 @
100’ of Pipe
2”
2 1/2”
3”
4”
4”
4”
4”
5”
700/850 @ 250’
of Pipe
2 1/2”
3”
4”
4”
5”
5”
5”
5”
Table 14 - Gas Supply Piping Size Chart for Boilers
Содержание MODCON500
Страница 35: ...LP 446 r4 Rev 10 12 16 35 Figure 29 Cascade Master and FollowerWiring...
Страница 57: ...LP 446 r4 Rev 10 12 16 57 Figure 35 500 Model Combustion System Replacement Parts...
Страница 58: ...LP 446 r4 Rev 10 12 16 58 Figure 36 700 850 Models Combustion System Replacement Parts...
Страница 60: ...LP 446 r4 Rev 10 12 16 60 Figure 38 Cabinet Replacement Parts All Models...
Страница 67: ...LP 446 r4 Rev 10 12 16 67 Maintenance Notes...
