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© 2020 Carrier
HESI SPARK ROD
The HESI spark rod comes in lengths from 14” (356mm) up to 180” (457 mm) in 2” (51mm) incre-
ments. The HESI spark rod features a positioning rod and a removable surface gap spark plug tip
designed for long life and ease of maintenance.
FIGURE 1.
High Energy Spark Rod Assembly
LENGTH SELECTION
The “L” dimension is the distance from the firing end of the spark tip back to the threaded connection
between the positioning rod and the weather head. In selecting a HESI spark rod length there are two
dimensions that make up the total rod length. One is the distance from the firing end of the spark tip
back to the burner front plate, and the other is the distance from the burner front plate back to the
threaded connections at the weather head. The total of these two distances equals the dimension “L”
of the HESI spark rod. Both dimensions can be obtained from a burner drawing if it is a retrofit
application. If this is a new HESI application the following general rules can be used:
GAS IGNITERS
Locate the spark tip at the upstream location of the primary combustion zone. Measure the distance
back to the burner front plate. Add 12” (305mm) to this distance for the amount of exposure outside
the burner front plate. The total of these two distances will be the dimension “L”. Refer to the HESI
spark rod drawing.
HESI POWER PACK
The HESI power pack comes in two voltages, 110 VAC and 220 VAC, 50/60HZ, and is housed in a
NEMA-4 junction box made of carbon steel painted gray or a NEMA-4X junction box made of
brushed stainless steel.
HESI INTERCONNECTING CABLE
This is a two conductor, prefabricated cable, sheathed in a flexible conduit with plug-in connectors at
both ends. The HESI is offered in 6’ (1.83), 9’(2.74m), 12’ (3.66m) and 15’ (4.72m) lengths.
HESI MOUNT TUBE -Fixed (optional)
The HESI Mounting Tube consists of a 1.05” (27mm) OD, carbon steel, with packing gland, locking
collar and quick release coupling. The mount tube is suitable for welding directly onto the burner
front plate and it provides support for the HESI rod. Select the mount tube length based upon the
HESI igniter length (see Ordering Information section). If the HESI is to be used in conjunction with
an oil igniter, please refer to the HESI Retraction Assembly.
