JOHNSON CONTROLS
35
SECTION 2 - START-UP AND OPERATION
FORM 102.20-OM2
ISSUE DATE: 6/01/2015
2
Both burners utilize a combustion air blower, and use
an exhaust blower, called an induced draft (ID) blower,
which keeps the combustion chamber at a slight nega-
tive pressure. Verification of this negative pressure and
other system parameters is part of a proper start up pro-
cedure.
Preliminary Coordination
Contact the contractor/customer who requested start-
up, and do the following:
•
Ensure the AHU and system is capable of design
airflow for gas heat start-up.
•
Ensure reliable power is available.
•
Verify the following:
•
Verify the AHU was properly started up.
•
Gas lines are purged of air to the equipment
valve.
•
Controls are complete.
•
Flue (stack) is correctly installed, if parts
were shipped loose.
Recommended Tools
•
Electrical Multimeter with Amprobe.
•
Heating AHU Installation and Operation Instruc-
tions, which are provided with every heating AHU
for technical information and troubleshooting.
•
Magnehelic Gauge 0-25 in WC, Dwyer Series
2000 or Model 1227 Dual Range Manometer for
checking pressure over fire (draft).
•
Control Signal Generator, 0 to 20 mA (Altek-234
or 334A) - For 2 to 10 VDC signal add 500 ohms
in series with signal generator.
•
Magnehelic Gauge 0-15 in WC and 0 to 3 lb (Dw-
yer series-2000) or Monometer (Dwyer- 1227)
Duel Range Monometer for checking supply gas
pressure and manifold gas or pilot gas pressure.
•
Honeywell - S7800A Test Module for use on
(Honeywell-7800) Series Relay Module, which is
available through Airside Parts
•
Flue Gas Analyzer (CO
2
and O
2
)
•
Stack Thermometer (0°F-1000°F approx.)
•
Digital Manometer (replaces Magnehelic Gauge):
Digital Manometer, Cat. #475-1 FM-AVSeries:
475-1 Mark III, Range: 0 to 19.99 In. W.C.from
Dwyer Instruments, Inc.
Pre-Start-Up Checklist
Condensate trap must be installed prior
to start-up by the installing contractor.
Refer to
for installing the gas
furnace condensate drain trap.
Use the following information to check the AHU be-
fore starting it:
•
Verify the AHU was properly started up, and that
airflow is at the design maximum for the heating
cycle. Refer to the air balance report.
•
Set the bypass damper, if provided.
• Airflow proving switch for main supply fan in
-
stalled and operational.
•
Check with the control technician: two-minute
post-purge programmed in AHU controller. Upon
call for unit stop, burner cycles off, then AHU fan
cycles off two minutes later.
