Krueger | 1401 N Plano Rd | Richardson, TX 75081 | 972.680.9136 | [email protected] | www.krueger-hvac.com
KAH Operation & Maintenance Guide
Page: 22 of 88
SECTION 2 - START-UP & OPERATION (CONTINUED)
Identify the Gas Burner Type
Two types of indirect fired gas burners are used on the
AHUs: Powerflame and the Eclipse series.
The
Powerflame
series offers a turndown (modulating ratio)
of 3:1 or 10:1. The Powerflame is easily identifiable by the
motorized gas valve with external linkage connecting the
air dampers on the burner air inlet.
The Eclipse series uses an air/gas ratio regulator with no
external linkage, and has a turndown range of 10:1 to 25:1
(sometimes greater). A visible external plastic tube is used
to transmit gas pressure from the burner to the regulator.
No external linkage is used.
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 negative
pressure. Verification of this negative pressure and other
system parameters is part of a proper start up procedure.
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 Instructions,
which are provided with every heating AHU for
technical information and troubleshooting.
•
Magnehelic Gauge 0-25” 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” WC and 0 to 3 lb (Dwyer
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 the Krueger Rep.
•
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-AV Series:
475-1 Mark III, Range: 0 to 19.99” WC from Dwyer
Instruments, Inc.