Startup
OAU-SVX005C-EN
31
After confirming gas flow to unit , verify and record gas
pressure at PG1.
3. Heating Starting Sequence for Gas Input Rating
400 MBh
Important:
Open shut off vales at MSO1, MSO2, and
Main Gas Valve (MGV) before proceeding.
•
The Main Gas Valve/Pressure Regulator (GV) and
Modulating Gas Valve (MGV) have been factory set
to achieve both proper maximum and proper
minimum fuel input to the direct gas-fired burner.
•
Gas supply train includes (2) factory installed
pressure gauges. Gauge 1 (PG1) reads the main gas
supply pressure. Gauge 2 reads the outlet pressure
to the burner from the MGV.
•
See Heater Burner Data Plate for factory pressure
settings.
•
Electrical control panel includes control relays with
pilot lights which, when illuminated, indicate the
relay is energized. For this starting sequence relays
controlling Outdoor Air Damper (R1), Indoor Fan
(R2), Heating Call (R6), Burner Proving (R7) and
Burner ON (R8) will be used.
•
Starting Sequence
Note:
In the event Outdoor Air Conditions or Unit
Controls are such that the unit will not
automatically enter the desired operating
modes, refer to Alarms and Troubleshooting
chapter for Control Override Procedures. For
initial heating start-up, it may be necessary to
remove and repeat the call for heat until the
internal gas piping system is bled.
–
R1 ON—OA damper OPEN
–
R2 ON—Indoor Fan ON
–
R6 ON—Call for Heating ON
–
R7 ON—Ignition Process begins and requires
proof of flame at burner to continue
–
R8 ON—Ignition Process Proven
4. Test Operating Heating Modes
Note:
Heating default control signal is 25 percent for
90 seconds following successful ignition.
Important:
•
This test is designed to assure adequate stable gas
pressure is available when burner is firing at maximum
capacity. Refer to unit nameplate rating for “Minimum
Gas Supply Pressure Required to Achieve Maximum
Temperature Rise.”
•
Depending on outdoor temperature, it may be
necessary to bypass the manual reset High
Temperature Limit control during this test.
a. High Fire Test Following Normal Burner Starting
Sequence
i. At ROD override, Heating Control Signal to
100 percent.
ii. When pressure at PG2 stabilizes, confirm PG1
and PG2 pressures are within ±5 percent of the
pressures shown on Burner Data Plate.
Figure 13.
Burner gas train
Burner Gas Train
• Manual Shut-off Valves (2) (MSO1 and MSO2)
• Main Gas Valve—Automatic Safety On-Off with Main Gas Regulator
• Modulating Gas Valve (MGV)
• Gas Pressure Gauges
• Main Gas Inlet Pressure (PG1)
• Burner Inlet Pressure (PG2)
KCC
International Inc.
MSO1
PG1
GV
MGV
PG2
MSO2
WARNING
Hazard of Explosion!
Failed gas components could explode or leak
flammable gas which could cause a fire resulting in
death or serious injury or property damage. To avoid
damage to unit if PG1 or PG2 exceed data plate
pre5 percent, disable incoming gas using the
manual shutoff valves and ensure incoming pressure is
within nameplate data BEFORE enabling the gas.
