Raypak Hi Delta 302A-902A Installation And Operating Instructions Manual

34Fig. 28: External LED Indicator DecalHeater Sequence of OperationModels 302A, 402A, 502A, 652A,752A and 902A1. The black (hot) wire lead goes directly to the mainpower switch. This black toggle switch is locatedat the middle front of the control compartment.2. When the main power switch is placed in the “ON”position, 120 VAC is applied to the 120 VAC termi-nal block on the circuit board and the 120/24 VACtransformer is powered.3. 120 VAC is waiting at the N.O. contacts of theEconomaster II pump delay.4. Terminals L1 and F1 of the ignition module arepowered with 120VAC.5. 120 VAC power is also applied to the controlpower connector on the circuit board.6. 120 VAC power is waiting at relay contacts K-3 toenergize the heater blower.7. The 120/24 VAC transformer outputs 24 VAC.8. 24 VAC is sent to the low water cut-off (optional)and the red power light is energized.9. 24 VAC is applied to the blue power light locatedon the diagnostic display board.10. 24 VAC is also applied to the red LED safety shut-down light on the front diagnostic board.11. 24 VAC is applied to the alarm circuit (optional). Ifthe E-5 sales option (Alarm) is included a 5 sec-ond time delay relay will not allow the alarm to so-und unless the circuit stays energized for morethan 5 seconds.12. Power is applied to terminal P1-1 of the U-2Board. All safeties are verified to ensure that it issafe to operate the heater. The safety compo-nents wired into the diagnostic board are: lowwater cut-off (optional), blocked vent switch, man-ual vent temp switch (optional), manual reset highlimit, low gas pressure switch (optional), high gaspressure switch (optional), and auto-reset highlimit (optional).13. Power is applied to terminal TP-1 of theEconomaster II pump delay to energize the circuitboard.14. Once all safeties have been verified to be closed,a 24 VAC signal is output from pin P3-16 of the U-2 Board.15. Relay K-1 (N.C.) will now be energized, and opensthe N.C. contacts to disable the alarm (optional)and turns off the red safety shutdown light.16. Pin P1-4 on the diagnostic board will now output a24 VAC signal to pin 1 of the “standby switch”.17. The “standby switch” (rocker switch) located at thelower left front of the control compartment is nowpowered. If the switch is “ON” and there is no callfor heat (CFH), the heater is in standby mode.18. After the standby switch is placed into the “ON”position, a 24 VAC signal is sent to the“enable/disable” connection (normally jumpered).19. 24 VAC switched power is applied to the S24V ter-minal on the ignition module.20. When the “enable/disable” contacts are closed,the 24 VAC signal travels to pin 1 of the stage 1connection and waits for a CFH.21. When a CFH occurs, a 24 VAC signal is sent to theCFH light on the diagnostics panel located on thelower left front of the control compartment.22. Power is now sent to terminal TP4 of theEconomaster II to energize the relay and close thecontacts.23. The heater pump is energized upon relay closureof the Economaster II.