Section 6, Wiring the Electrical System
6-4 Installation Manual for Oasis
®
SCH33™ HW Heating System
• Fuses – The control board contains four fuse holders
with fuses pre-installed. These are standard,
automotive, spade type fuses available from most auto
parts stores.
• Thermal Cutoff - The heater burner box contains a
non-resettable thermal cut-off that will provide
protection against an overheat condition within the
burner box. If activated, the thermal cut-off will stop the
fuel flow to the burner nozzle. If the thermal cut-off is
triggered, the reason for this must be investigated and
resolved. The thermal cut-off must be replaced once it
has been activated.
• Accessory terminal block – The following components
need to be wired into the accessory terminal block on
the control board:
o Thermostats (up to four). Additional 4 zone
board available for larger applications.
o Fan heaters
o Fan speed switches (between F1-F4 and the
fans)
o Internal Circulation pump (12 vdc)
o Domestic water aquastat (optional)
o Engine-heat aquastat (optional)
• Fault bypass and reset buttons – These buttons
allow testing of the heating system by by-passing the
fault-sensing circuit. This fault bypass feature is
engaged by depressing and holding the top button,
depressing and releasing the bottom button, and then
releasing the top button. To reset the heater, turn the
heater service switch OFF, then ON again.
Do not leave heater running unattended in bypass mode.
Bypass mode runs for five (5) minutes.
• Test points –on the control board allow troubleshooting
of the heating system. For detailed information on the
use of each test point. See Section 10, pg. 10-11.
• Diagnostic display – is used to diagnose heater
operating and fault conditions. The display also has
signal lights for heater power and circulating pump
operation.
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