Burnham MEGASTEAM MST288 - Manual (Page 47)

4
ii. Check Safety Features
Safe Start:
• Place a jumper across cad cell terminals.
•
Follow procedure to turn on burner.
Burner must not start, indicator light turns
on and control remains in Idle Mode.
• Remove jumper.
iii. Simulate Ignition or Flame Failure:
• Follow procedure to turn on burner.
• Close hand valve in oil supply line.
• Failure occurs, device enters Recycle
Mode. Indicator light flashes at ¼ Hz rate
2 seconds on, 2 seconds off).
• Device tries to restart system after
approximately 60 seconds.
• After third Recycle Mode trial, safety
switch locks out within safety switch
timing indicated on label and control
enters Restricted Mode. Indicator light
flashes at 1 Hz rate (½ second on, ½
second off). Ignition and motor stop and
oil valves closes.
Figure 6: Cad Cell Location
• If safety switch shuts down burner and
resistance is above 1600 OHMS, open line
switch to boiler. Access cad cell under
ignitor, clean face of cad cell and see that
cell is securely in socket. Check gasket
around perimeter of ignitor lid for proper
seal. If gasket is missing or damaged,
replace gasket. Room light can effect cad
cell resistance. Reset safety switch.
• Close line switch to boiler. If burner starts
and runs beyond safety switch cut-off
time, cell is good. If not, install new cell.
v. Power Failure Check: After Flame is
established, turn the power off to the control/
burner. The burner should shut down safely.
When power is restored a normal ignition
sequence should be started.
3. WARNING — Check Pressure Limit Control
— Jumper Thermostat Terminals. Allow burner to
operate until shut-down by limit. Installation is not
considered complete until this check has been made.
WARNING
Jumper must be removed after this check.
4. Check low water cut off control with water level at
normal water line (see Figure 1). Raise thermostat
setting to allow burner to operate. Open boiler drain
to allow water level to drop to bottom of sight glass
until burner operation is shut-down by low water
cut-off.
Close boiler drain and refill to normal water line.
Burner should automatically restart during fill.
Lower thermostat setting.
5. Check operating control on boiler equipped with
tankless heaters. With burner off, draw hot water
until burner starts, then turn off hot water and check
burner shut-down.
J. IF CONTROLS DO NOT MEET
REqUIREMENTS outlined in Paragraph I.,
replace control and repeat checkout procedures.
iv. Cad Cell Check: See Figure 26.
• Perform cad cell resistance check as
outlined in control feature. If resistance is
below 1600 OHMS and burner runs
beyond safety cut-out time, cad cell is
good.