Midco HMA-2 & HMA-2A Series - Manual (Page 11)

Midco International Inc.
11
8471 34
Installation
___________________________________
Burner operation depends on the unit control setup in which the HMA-2 & 2A burner is used. A
typical setup should consist of a Flame Safety Control with appropriate air fl ow proving system and
a Modulating Gas Control System.
1. Verify the pressure across the burner. The pressure across the burner can be measured by
placing two static pressure probes, one downstream and one upstream of the profi le opening
and measure the differential pressure. The pressure should be within burner operating
specifi cations and within the expected calculated pressure. See Chart 2
2. With the burner off check the Flame Safety Air Proving System
a. Check the operation of the air proving system for low and high airfl ow setting. Refer to
the Specifi cations of the Flame Safety Control for setup instructions and air switch
operational characteristics.
Burner Setup
Flame Rod
Pilot
Spark Rod
Burner
Union
Modulating
Valve
Main Manual
Gas Valve
Combination Gas Valve
with Main & Pilot Regulator
Manual Firing
Valve
*
Manual
Pilot Valve
Pilot
Regulator
Pilot
Main Gas
Pressure
Tap
Burner
Pilot Tube
Union
Manual Firing
Valve
Modulating
Valve
Main
Manual Gas
Valve
Main
Regulator
Main
Operating
Valves
Safety Shut-off
Valve
Pilot Gas
Pressure Tap
Flame Rod
Spark Rod
* A manifold pressure tap
needs to be provided
at the burner to check
manifold pressure
*
Direct Spark Ignition
Typical
Gas Train Assembly
Direct Spark Ignition
Typical
Gas Train Assembly
400,000 BTU/Hr
and Under
Typical Gas Train Assembly
Continued
Figure 5b - Direct Spark Gas Train Assemblies