Murphy DF Series User's Manual
Contents
1. i For Electrical Tbe sara Connection DF756 only standard 5 5 8 in 143 mm TYPICAL APPLICATIONS Raw Water Tank Clear Water Tank OPL Series Transfer SWICHGAGE Pump yw Injection Pump Typical Water Flood Control System The diagram above displays eight DF Series switches installed on a transfer pump As tank level falls to predetermined low level DF 6 Raw Water tank and a Clear Water tank When raw water rises to Starts the transfer pump If the tank level continues to fall due to the predetermined level DF 1 stops the supply pump As tank level failure of the filters section DF 7 initiates shutdown of the transfer falls below the predetermined level DF 2 starts the supply pump If pump DF755 located at this level will also operate backwash the tank level continues to fall DF 3 initiates shutdown of the sup equipment DF 8 stops injection pump before tank pumps com ply pump DF 4 stops transfer pump before raw water tank is com pletely out pletely pumped out An OPL Series pressure SWICHGAGE stops injection pump when When clear water reaches the predetermined level DF 5 stops the pressure reaches predetermined high or low pressure Tank with Low Pressure Typical Tank Mounting Methods DF755 Gas Blanket DF755EX The DF755EX below is shown installed on a crude oil tank where a low pressure gas blanket is used to prevent evaporation loss It is mounted directly to th2. switch and movement assembly repair kit 5 amp 15000118 Screws 2 for switch assembly to case 6 32 x 1 4 round head 80040605 Actuator assembly repair kit 15000119 Diaphragm repair kit 15000123 Bottom Plate 1 NPT connection 15050083 Screw 1 8 32 x 1 4 round head 800408 14 Terminal cup washer 00000827 Plug 1 8 plastic pipe hex DF755EX 86060203 Connector 1 4 tube x 1 8 pipe male DF756 85030402 Plug 1 2 NPT hex brass 86060801 SPDT snap switch and insulator repair kit 5 amp 15000117 MURPHY gt FW Murphy P O Box 470248 Tulsa Oklahoma 74147 USA 1 918 317 4100 fax 1 918 317 4266 e mail sales fwmurphy com www fwmurphy com P 0 Box 1819 Rosenberg Texas 77471 USA 1 281 633 4500 fax 1 281 633 4588 e mail sales fwmurphy com MURPHY DE MEXICO S A DE C V San Luis Potosi L P M xico 78384 52 444 8206264 fax 52 444 8206336 Villahermosa Office 52 993 3162117 e mail ventas murphymex com mx www murphymex com mx CONTROL SYSTEMS amp SERVICES DIVISION Blvd Antonio Rocha Cordero 300 Fracci n del Aguaje DF757 Cover aluminum 15050081 Case aluminum 15050594 Cover Screw 3 6 32 x 5 16 round head 80040607 SPDT snap switch and bracket assembly repair kit 5 amp 15000174 Screws 2 for switch bracket and assembly to case 6 32 x 1 4 round head 80040605 Spring and piston assembly repair kit 15000190 Diaphragm repair kit 15000123 Bottom Plate 1 NPT connection 15050083 SPDT snap switch and
3. the liquid being measured For proper pressure to level ratio the minimum dimensions of the volume cell should be 6 in 152 mm inside diameter and 3 in 76 mm inside depth The sensor line can be of any diameter or material either flexible or solid as long as it is of sufficient length to reach from the volume cell to the desired loca tion for the DF755 All fittings and connections should be air tight to avoid loss of charge Tube lengths longer than 4 ft 1 2 m should have provision for periodic air purging Installation of the Volume Cell Install the volume cell according to the level you wish the pump to start and stop Secured the volume cell with a substantial bracket which will not allow the cell to be floated or tilted when the water level rises The DF755 should be DF755 installed well above the highest water level and in a position that will allow access for adjustment or repair Sensor Line NOTE Periodically operate pump manually until water level reaches a point approximately 1 2 in 13 mm below bottom of the volume cell This will automatically re charge the unit and compensate for normal absorption of air into water Small electric air pumps are available to automatically charge system at all times MACT1 Tube Kit Volume Cell MAC1 DF 94063N page 3 of 4 TYPICAL WIRING Starts at Low Level Stops at High Start motor when predetermined low level is reached and st
4. DF 94063N Revised 09 03 Section 15 Installation and Operation of the ection 18 DF Series Hydrostatic Head Level Switches Qo Please read the following information before installing A visual inspection of this product for damage during shipping is rec ommended before mounting It is your responsibility to have a qualified person install this unit and make sure it conforms to NEC and local codes GENERAL INFORMATION VE EREA p WARNING BEFORE BEGINNING INSTALLATION OF THIS MURPHY PRODUCT V Disconnect all electrical power to the machine V Make sure the machine cannot operate during installation V Follow all safety warnings of the machine manufacturer V Read and follow all installation instructions Description The DF series are diaphragm operated hydrostatic head pressure level switches A pressure sensitive diaphragm operates a snap switch that can be wired directly to electric pilot circuits to control pumps at predetermined levels Typical application is to start and stop electric driven pump s to maintain tank levels It is also applicable to engine driven pumps CAUTION Certain dangers to human safety and to equip ment may occur if some equipment is stopped without pre warning It is recommended that monitored functions be limited to alarm only or to alarm before shutdown The Nitrile sensing diaphragm is impervious to most liquids and is sensitive enough to control levels with 1 4 in 6 mm repeatabil
5. e side of the tank or on riser pipe 4 to 7 in 102 to 178 mm below level to be controlled Pump automatically stops or starts when liquid reaches predetermined high or low level A Bull Plug Installation Tank Wall Mounting With Drain Cock Fuel Tank Gas Blanket H F iF Gas Liquid a a Directly Riser Pipe On Tank Method Tank Wall Mounting DF 94063N page 2 of 4 BASIC OPERATION DF755EX DF755 a Vent DF755EX or Tube Fitting DF756 Hydrostatic Head oe Pressure As the liquid level rises hydrostatic head pressure is applied to the diaphragm A The diaphragm is forced upward forcing the actuator arm B to activate the snap switch 6 Models DF755 and DF755EX are factory set and operate at approximately 2 in 51 mm and 6 in 152 mm rising above the level at which the diaphragm is mounted The switch resets back to normal condition at approx 2 inches 51 mm falling level The trip point s for Model DF757 are adjustable between 2 in 51 mm and 110 in 2794 mm for high and low make break operation by knobs D For sealed tanks model DF755EX can be fitted with a tube fitting to bal ance the top of the diaphragm chamber to a tank gas blanket see Typical Applications The DF755EX is supplied with an atmospheric vent fitting Hydrostatic Head Pressure Hydrostatic Head Pressure A Setpoint Adjustment DF757 1 Loca
6. insulator repair kit 5 amp 15000230 FRANK W MURPHY LTD Church Rd Laverstock Salisbury SP1 1QZ U K 44 1722 410055 fax 44 1722 410088 e mail sales fwmurphy co uk www fwmurphy co uk MURPHY SWITCH OF CALIFORNIA 41343 12th Street West Palmdale California 93551 1442 USA 661 272 4700 fax 1 661 947 7570 e mail sales murphyswitch com www murphyswitch com MACQUARRIE CORPORATION 1620 Hume Highway Campbellfield Vic 3061 Australia 61 3 9358 5555 fax 61 3 9358 5558 e mail murphy macquarrie com au USA 1SO 9001 2000 FM 28221 UK 1SO 9001 2000 FM 29422 In order to consistently bring you the highest quality full featured products we reserve the right to change our specifications and designs at any time DF 94063N page 4 of 4 Printed in U S A
7. ity See model descriptions for limits of switch trip point adjustability Materials include aluminum body nylon bottom plate and a special alloy leaf snap switch as standard This simple level switch is highly reliable and can be worked into most new or existing system without major modification or special tools DF755 and DF757 are suitable for atmospheric tanks in a non haz ardous location The SPDT snap switch for the DF755 is preset for a 4 in 102 mm differential in liquid level operating at approx 6 inches 152 mm ris ing and resetting at approx 2 inches 51 mm falling level The DF757 trip point is adjustable over a 108 inches 2743 mm dif ferential Specifications Snap switch Ratings SPDT standard all models 5 A 125 250 or 480 VAC 1 2 A 125 VDC 1 4 A 250 VDC Case Lid Aluminum standard all non explosion proof models Bottom Plate Glass filled nylon Process Connection 1 NPT standard Maximum Pressure Rating 25 psi 172 kPa 1 72 Bar Conduit Connection electrical 1 2 NPT Warranty A limited warranty on materials and workmanship is given with this FW Murphy product A copy of the warranty may be viewed or printed by going to www fwmurphy com support warranty htm DF 94063N page 1 of 4 DF755EX DF755 and DF757 p 5 1 2 in a do fae 1 2 NPT 140 mm eon For Electrical ap Connection 6 5 32 in 156 mm 1 NPT standard 1 2 NPT 1 4
8. op when high level is reached Keeps tank level within selected limits Motor starter equipped with H O A HIGH N O oF DF755 1 DF755 2 MOTOR Single Magneto Shutdown Wiring of magneto to N O switch terminal will shut down engine at prede termined high level shown below Wire to N C terminal to shutdown on low level MAGNETO ON O 9C oNC Starts at High Level Stops at Low Start motor when predetermined high level is reached and stop when low level is reached Motor starter equipped with H O A HIGH N O DF755 DF755 2 MOTOR Dual Magneto Shutdown Shutdown dual magneto engines using Murphy MS2120 Magnetic Switch Diagram below shows hookup for low level shutdown Wiring changes and mounting locations are necessary for high level shutdowns Model MS2120 Jumper 2 amp 5 SERVICE PARTS DF755 Description Part Number Cover aluminum 15050081 Case aluminum 15050082 Cover Screws 3 6 32 x 5 16 round head 80040607 SPDT snap switch and movement assembly repair kit 5 amp 15000122 Screws 3 for switch assembly to case 6 32 x 1 4 round head 80040605 Diaphragm repair kit 15000123 Bottom Plate 1 NPT connection 15050083 Bracket and movement repair kit 15000313 SPDT snap switch and insulator repair kit 5 amp 15000121 DF755EX Cover aluminum 15050154 Case aluminum 15050155 Gasket 15050305 SPDT snap
9. te threaded adjustment shaft and adjustment knobs see drawing above 2 To increase low level setpoint rotate lower knob counterclockwise NOTE If adjustment shaft turns when rotating adjustment knobs grasp the adjustment shaft with a pair of needle nose pliers then rotate knob zz al mH LLULLU INN USING THE DF755 WITH MAC1 VOLUME CELL ACCESSORY The MAC1 Volume Air Cell when attached to the DF755 can monitor water levels on a sump Activate alarms or start a pump directly The MACI Volume Air Cell is non corrosive and provides 1 4 20 stainless steel mounting studs The MACT1 Tubing Kit provides 4 ft 1 2 m flexible non corrosive 1 4 in 6 mm tubing cut to fit The kit includes necessary fittings to attach tubing Both the MACI air cell and MACT1 tubing kit are available from Murphy Volume Cell Operation As liquid rises around the volume cell it compresses air inside the cell and forces it up in the sensor line As air pressure increases due to the water level continuing to rise sufficient pressure will be applied to acti vate the internal snap switch which in turn starts the pump As the liq uid level is pumped down pressure decreases and the above procedure is reversed The pump is stopped and held in a standby condition An air purge may be required in the sensor line Consult factory Choosing a Volume Cell The volume cell should be constructed of material which will be unaf fected by
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