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HomeMy WebLinkAbout303.004a - Class 1 Pressure Governor TRAINING AND EQUIPMENT MANUAL PUMPS 303.004a CLASS 1 PRESSURE GOVERNOR EFFECTIVE: DECEMBER 2018 Current Revision Date: 12/26/18 Next Revision Date: 12/26/23 Author’s Name/Rank: Robert J. Garcia, Engineer Review Level: 1 PURPOSE Outline the use and operation of the Class 1 Pressure Governor. APPLICATION The Class1 Pressure Governor is designed to maintain a selected pump pressure or engine speed setting. OPERATIONAL POLICY This section intentionally left blank. OPERATIONAL GUIDELINE This section intentionally left blank. PROCESS When the unit is first powered up, the display will show [MODE] and the engine will remain at idle until the mode switch is pressed to select the desired operating mode (PSI MODE or RPM MODE). An internal relay is to be used to turn on the remote throttle at the engine ECU. This relay will not energize until the MODE switch is pressed and a valid throttle ready input is present at Pin 2 of the 12 pin connector. If the pump is engaged and the “OK to Pump” LED is illuminated, PRESSURE will be the first mode selected otherwise THROTTLE will be the first mode. Section 303.004a Page 1 of 4 RPM Mode When the unit is in RPM mode, the display will read “THROTTLE” and the green RPM LED will be illuminated. Engine speed is controlled by the INC (increase) and DEC (decrease) switches, the display will indicate “INCREASE” or “DECREASE” as appropriate when these switches are depressed. The governor will maintain the last output signal attained with these switches. The engine will maintain an RPM appropriate for the throttle signal being sent. NOTE: If, while operating in rpm mode the pressure increases more than 50 psi from the pressure logged at the last switch press, the governor will limit the pressure increase to no more than a 50 psi differential. The governor may reduce engine rpm to achieve this and the message psi limit will be displayed in the message center. The governor will not attempt to regulate pressure in this mode; only limit the differential pressure to 50 psi from the pressure present when the last switch was pressed. Pressure Mode When the unit is operating in the Pressure mode, the display will show “PRESSURE” and the amber PRESSURE LED will be illuminated. Pump pressure is set by using the INC (increase) and DEC (decrease) switches. The governor will attempt to maintain the last pressure achieved with these switches. The display will indicate “INCREASE” or “DECREASE” as appropriate. The governor maintains pump pressure by controlling engine RPM in response to a signal from the pressure transducer mounted on the pump. When controlling in this manner, the display will show “CTRL DEC” or “CTRL INC”. INFORMATION Pressing the mode switch will change the governor from RPM to Pressure mode without a significant change in engine speed or pump pressure. The message center will indicate “PRESSURE” or “THROTTLE” as appropriate once the mode change has been made. When switching to PRESSURE, the pressure set point is whatever pressure is on the transducer at the change. Section 303.004a Page 2 of 4 Preset Mode Pressing the PRESET switch in either mode will control the engine to attain the preset RPM or pump pressure programmed in governor memory. If there is more than 10 PSI pressure on the pump, the RPM Preset is disabled and the Message Center will display “DISABLED”. High Idle Mode An input is available to bring the engine speed to a PRESET RPM (High Idle) from a remotely mounted switch. While operating in this mode, the display will show “HIGHIDLE”. This function is inoperative when the pump engaged input is active, there is more than 10 PSI on the pressure transducer or if the MODE switch on the governor has been pressed. Pressing the IDLE switch causes the high idle to drop out and the high idle input must be toggled off and then on again to reinstate high idle. The INC and DEC switches are active in high idle mode and the engine speed can be adjusted, changing engine speed in this manner will not change the preset RPM that is set in memory. Idle Mode Pressing the IDLE switch at any time returns the engine to idle speed. Switch Session Pressure Increase If the INC switch is held the governor will not allow a change greater than 80 PSI without releasing the INC switch and pressing it again. This is only applicable when the discharge pressure is above 90 PSI. This function prevents high pressures from being introduced by a distracted operator. Pressure / Water Loss If the discharge pressure drops below 30 PSI for any reason, engine speed will not be increased. The governor output voltage will reduce to the last known value (engine RPM) where the pressure set point was obtained. The display will flash “INTAKE” during this low pressure condition. If the pressure increases above 30 PSI, “OPERATOR” will flash and the governor will not increase output unless the operator presses the INC or PRESET switches. If pressure above 30 PSI is not regained within 5 seconds, the governor will return the engine to idle and display “LoSupply”. The operator must make certain the water supply is adequate and then reinstate governing using the MODE, INC and/or PRESET switches. Section 303.004a Page 3 of 4 Pressure Recovery / Cavitation (TRIM) The governor has a trim adjustment; this can be set between 5% and 20% of maximum throttle. This parameter limits the governor’s maximum increase in a pressure recovery attempt. The message center will flash “OPERATOR” when this limit is reached and the RPM will not increase further. The operator must take positive action to restore discharge pressure. If pressure is not restored within 4 seconds, the governor will reduce output to the last known output where pressure was maintained. The operator must input a new set point with the INC/DEC or PRESET switches. If the pressure rises above the original set point and the governor controls a decrease in engine speed, the governor will return to normal operation and “PSI MODE” is displayed. For more information, access the Class 1 Pressure Governor Operators Manual at the following link: Governor. DEFINITIONS This section intentionally left blank. CROSS REFERENCES No cross references recognized. Section 303.004a Page 4 of 4