8587 Preheaters heat and maintain heavy fuel oils at proper
temperatures for combustion.
They are installed horizontally in fuel lines or at oil pump sets. Low
watt density (12 Wsi) and reduced surface temperatures minimize
carbon formation on heating elements.
Each unit has an integral thermostat with a standard fi eld adjustable
range of 100°F to 225°F. A 3-pole contactor, actuated by the
thermostat, is required. If a heater is ordered with a contactor, the
contactor is assembled to the heater assembly. See Dwg. OA6-0179
for schematic fi eld wiring.
Heater shells are Schedule 40 seamless pipe, designed for 150 psi
maximum pressure at 275°F maximum temperature. Standard heaters
are off ered for 208, 230, and 460 V ac 3-phase supply voltage. For
other supply voltage inputs, consult with North American.
Heater capacity depends on temperature rise and gallons per hour of
oil; e.g., ratings for a typical heater might be:
64 gph through 100 degree rise, or
43 gph through 150 degrees, or
128 gph through 50 degrees.
Use this formula:
Watts = gph × degrees rise
heat 50 gph from 50 F to 200 F
50 × 150 = 7500 watts (7.5 kW)
Good practice calls for adding 20-30% for heater shell
and piping losses. Therefore, this heaters rating should
be at least 9.0 kW, and correct selection is the 8587-10
(10 kW) heater.
Heaters must be installed horizontally with oil inlet and outlet facing
directly upward. Whenever heating element is removed from shell, it
must be reinstalled with thermostat sensing tube uppermost; and shell
must be full of oil before heater is turned on.
Thermostat settings are fi eld adjusted by rotating the dial
pointer. Pointer settings:
4 to 5: Approximately 125°F oil temperature
8: Approximately 185°F oil temperature
10-11: Approximately 225°F oil temperature
A cold oil interlock switch is factory set at 125 F; it can be adjusted
by turning a knurled knob under the dial pointer (per instructions on
Heating unit should be withdrawn from shell at least once a year and
cleaned with trichlorethylene or an equivalent solvent (avoid getting
the solution on the electric control unit or heater connections).
Use alternating current only.
A. HEATER TABLE
(For other sizes and options, consult North American.)
B. CONTACTOR TABLE
(120 V coil isstandard)
Contactors with 240 V, 50-60 Hz coil are available at same
prices as the above 120 V 60 Hz contactors, but they are not
stocked by North American. 240 V is maximum allowable for
Ref: Dwg. OA6-0179
North American Fuel Oil Heaters Electric