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Maintenance

17

Removing the Resistor

Numbers in brackets [ ] refer to the labeled parts in Figure 7. Parts may 
appear slightly different than what is shown for some models.

1. Disconnect the load from the RF line and the interlock control box, remove 

the water hoses, and drain off any water still in the load.

2. Turn the load on end with the hose fittings up.

3. Remove the screws from the back of the water chamber assembly. These 

secure the water chamber assembly to the load housing [0].

Note:

The 8731 has only one screw, on the side of the water cham-

ber assembly. Also, the water chamber is threaded, and screws into 
place. Turn the water chamber counterclockwise until the threads dis-
engage before pulling the assembly out.

4. Pull the water chamber assembly out. 

Note:

It may be necessary to rock the chamber gently while pulling.

Note:

If the resistor is intact then the entire resistor assembly [2] 

may be pulled straight out of the load housing.

Inspection

When the resistor has been successfully removed, inspect it carefully to insure 
that it has not been fractured. In most cases, even in the event of complete 
resistor burnout the resistor will remain intact.
Examine the inside of the load housing and water chamber for damage to inter-
nal parts, especially the resistor O-Ring seal and the resistor contact strip. If 
the O-Ring has cracks or if the contact strip has missing fingers, replace them. 
If the resistor did fracture, thoroughly rinse all parts under clear running 
water and dry before any assembly.

Replacing the Resistor

1. Insert the plugged end of the new resistor into the resistor fitting of the 

center conductor assembly [8] to test its tightness.

2. The resistor should be snug but should not have to be forced into the fitting. 

Note:

If the resistor is too loose, press the fitting fingers together 

slightly and try the resistor again. Continue closing the ends of the 
resistor fitting until a snug fit is obtained.

WARNING

If the resistor breaks, there may be splinters or sharp pieces inside the load 

housing. Be careful when repairing to avoid being cut.

CAUTION

Do not remove the resistor plug. Any attempt to do so will cause leakage 

and resistor damage.

Summary of Contents for ECONOLOAD 8730 Series

Page 1: ...SISTOR SERIES 8730 INCLUDING MODELS 8730A 8731 8732A 8738A AND 8738A110 Copyright 2009 by Bird Electronic Corporation Instruction Book P N 920 8730S Rev D Econoload and Termaline are Registered Trademarks of Bird Electronic Corporation ...

Page 2: ...This Page Intentionally Left Blank ...

Page 3: ...r is present WARNING Do Not Service Or Adjust Alone Under no circumstances should any person reach into an enclosure for the purpose of service or adjustment of equipment except in the presence of someone who is capable of rendering aid WARNING Safety Earth Ground An uniterruptible earth safety ground must be supplied from the main power source to test instruments Grounding one conductor of a two ...

Page 4: ...ppears on the equipment indicating there is important information in the instruction manual regarding that particular area This symbol indicates that the unit radiates heat and should not be touched while hot WARNING Disconnect the unit from all power sources before servicing The unit may be energized from multiple sources The potential for electric shock exists WARNING Improper wiring could resul...

Page 5: ...trol systems are used for 115 Vac and 230 Vac Use the correct interlock control for the specific voltage CAUTION If installed connect optional interlock before applying RF power CAUTION Do not contaminate the coolant with pipe sealant CAUTION Do not interrupt coolant supply Even momentary application of RF power while coolant is not circulating could cause immediate destruction of the load CAUTION...

Page 6: ...DEL INSTRUMENTO BENUTZUNG WIRD DAS GERÄT AUF ANDERE WEISE VERWENDET ALS VOM HERSTELLER BESCHRIEBEN KANN DIE GERÄTESICHERHEIT BEEINTRÄCHTIGT WERDEN UTILISATION TOUTE UTILISATION DE CET INSTRUMENT QUI N EST PAS EXPLICITEMENT PRÉVUE PAR LE FABRICANT PEUT ENDOMMAGER LE DISPOSITIF DE PROTECTION DE L INSTRUMENT IMPIEGO QUALORA QUESTO STRUMENTO VENISSE UTILIZZATO IN MODO DIVERSO DA COME SPECIFICATO DAL P...

Page 7: ...LTEN NUR FÜR GESCHULTES FACHPERSONAL ZUR VERMEIDUNG GEFÄHRLICHE ELEKTRISCHE SCHOCKS SIND WARTUNGSARBEITEN AUSSCHLIEßLICH VON QUALIFIZIERTEM SERVICEPERSONAL DURCHZUFÜHREN ENTRENTIEN L EMPLOI DES INSTRUCTIONS D ENTRETIEN DOIT ÊTRE RÉSERVÉ AU PERSONNEL FORMÉ AUX OPÉRATIONS D ENTRETIEN POUR PRÉVENIR UN CHOC ÉLECTRIQUE DANGEREUX NE PAS EFFECTUER D ENTRETIEN SI L ON N A PAS ÉTÉ QUALIFIÉ POUR CE FAIRE AS...

Page 8: ...NCHER LE VERROUILLAGE À L ÉMETTEUR AVANT EMPLOI CONECTE EL INTERBLOQUEO AL TRANSMISOR ANTES DE LA OPERACION VOR INBETRIEBNAHME VERRIEGELUNG AM SENDER ANSCHLIESSEN PRIMA DI METTERE IN FUNZIONE L APPARECCHIO COLLEGARE IL DISPOSITIVO DI BLOCCO AL TRASMETTITORE ...

Page 9: ...o load Econoload or Load The entire unit It contains the RESISTOR Resistor A subcomponent of the LOAD This is the ceramic resistor which actually absorbs the RF power Literature Contents Chapter Layout Introduction Describes the features of the Econoload RF Load lists equipment supplied and optional equipment and provides power up instructions Theory of Operation Describes how the load works on a ...

Page 10: ...viii ...

Page 11: ...lorimetry 3 Chapter 3 Installation 5 Unpacking and Inspection 5 DC Resistance 5 Placement 5 Coolant 5 Hoses 5 Interlock Optional 6 Thermoswitch 8732A Only Optional 7 Installing the Thermoswitch 7 Connecting the Thermoswitch to the Interlock 7 Connecting the RF Power 8 Using a Swivel Flanged Coupling 8 Using an Unflanged Coupling 8 Using a Slotted Connector Sleeve for Model 8738A110 9 Chapter 4 Ope...

Page 12: ...ing the Safety Light 15 Servicing the Resistor 16 Removing the Resistor 17 Inspection 17 Replacing the Resistor 17 Replacing the Conductor 18 Storage and Shipment 18 Storing the Load Resistor 18 Shipping the Load Resistor 18 Customer Service 19 Specifications 20 Replacement Parts 21 Bird 8730A 8732A and 8738A 21 Bird 8731 21 Bird 8738A110 21 Interlock Optional 21 Limited Warranty 22 ...

Page 13: ...nd TV modulation and certain pulse types Contact Bird Electronic Corporation for information on using Econoloads with pulsed signals z Designed for easy field repair of all components Items Supplied z Load Water cooled z Instruction Manual Optional Items z Control system with red pilot light that turns on when the load is working properly Also has flow switch and 12 second time delay inter lock to...

Page 14: ...Introduction 2 Figure 1 8730 Series Econoload Outline Drawing ...

Page 15: ...witch is a normally open type and is closed during normal operation After flow is restored a time delay switch keeps the interlock open for an additional 12 seconds This ensures proper operation of the cooling system before applying RF power preventing resistor burnout Optional Thermal Interlock 8732A Only The 8732A can be supplied with an optional passive overtemperature thermo switch Normally cl...

Page 16: ...Theory Of Operation 4 ...

Page 17: ...ad so that the warning label is visible and the water connections are easily accessible z Access to a coolant supply or pump is required Make sure the coolant supply can meet the required flow rate z To use the optional interlock AC power is required Coolant For operation at 1kHz or lower use only distilled water as the coolant For opera tion above 1kHz use distilled or potable water Refer to the ...

Page 18: ...l 2 Figure 2 Interlock Connections WARNING Disconnect the unit from all power sources before servicing The unit may be energized from multiple sources The potential for electric shock exists WARNING Improper wiring could result in electric shock and death CAUTION If installed connect optional interlock before applying RF power CAUTION Different control systems are used for 115 Vac and 230 Vac Use ...

Page 19: ...he thermoswitch jack B 3 Unscrew the small knurled cover fitting from the base plug D of the con nector to release the base 4 Thread the control switch wires through the clamp E with the washers F inside and its threaded fitting in place 5 Use short tips on the wires and put spaghetti sleeves over the ends if necessary 6 Solder the switch leads to the lugs G of the connector base Note The ring nut...

Page 20: ...the bolt sets and tighten evenly all around to transmission line manufacturer s recommended torque Note Use all of the bolts Using an Unflanged Coupling To couple the unflanged connector with an unflanged RF line use an appro priate coupling kit Refer to Figure 5 while following the instructions below Figure 5 Unflanged Coupling 1 Insert the center bullet and bottom it on the midpoint nibs 2 Posit...

Page 21: ...nector use an appropriate coupling kit 1 Insert the center bullet and bottom it on the center conductor 2 Position a clamping band over the input connector 3 Slide the slotted outer conductor of the load input over the unflanged transmission line until it is seated 4 Tighten the clamping band ...

Page 22: ...Installation 10 ...

Page 23: ...wer at the source Operation with the Optional Interlock 1 Turn on AC power to the interlock control box 2 Turn on the coolant supply Note Minimum flow rate is 4 gal min 15 L min at 5 C 40 F The minimum flow increases linearly up to 6 gal min 23 L min at 60 C 140 F 3 Listen for the flow switch to close it will click when it closes 4 Wait about 12 seconds Note The time delay switch should close and ...

Page 24: ...g Down 1 Turn off RF power at the source 2 Wait at least five minutes for the Econoload to cool 3 Turn off ac power to the interlock control box 4 Turn off the water supply Always do this last Emergency Shutdown Turn off RF power at the source ...

Page 25: ... functioning Inspection Routinely inspect the following components z Load Check the center and outer conductors for visible damage or excessive wear z Hoses Check for cracks or deterioration Make sure the hoses are securely fastened to the load Problem Possible Cause Correction Transmitter won t turn on or shuts off repeatedly Overheating Increase water flow Lower the ambient temperature Insuffici...

Page 26: ...RF power and interlock circuitry 2 Disconnect the RF line 3 Connect the multimeter test leads to the center and outer conductor of the load Refer to Figure 6 4 Compare the measured value with the previous measurement and with the baseline resistance measured when the load was put into service Note If the new value differs from either of these by more than 2 ohms this could indicate a failing resis...

Page 27: ... the top of the relay clamp 5 Press the clamp legs in slightly to release the relay 6 Pull the relay cartridge straight out of its socket 7 Insert the new relay cartridge and rotate it to align the opening in the cartridge with the center post nub in the socket 8 Make sure that the clamping prongs fit into their matching slots 9 Tighten the clamp screw to secure it 10 Turn on the interlock ac powe...

Page 28: ... are available Figure 7 Load Exploded View Model 8730 WARNING Disconnect the unit from all power sources before servicing The unit may be energized from multiple sources The potential for electric shock exists Outer Conductor Label Nipple Locations Housing Water Chamber Screws Screws Outer Conductor Housing Flange Center Conductor Assembly Housing Flange Center Conductor Assembly Teflon Disk DETAI...

Page 29: ...essfully removed inspect it carefully to insure that it has not been fractured In most cases even in the event of complete resistor burnout the resistor will remain intact Examine the inside of the load housing and water chamber for damage to inter nal parts especially the resistor O Ring seal and the resistor contact strip If the O Ring has cracks or if the contact strip has missing fingers repla...

Page 30: ... outer conductor assembly 12 Note NOTE To only replace the outer conductor install it now and screw it into place 3 Remove the center conductor assembly 11 by pulling it carefully out of the load housing 0 4 Make sure the resistor 1 and inner flow tube 9 do not come out with the center conductor 5 Insert the new center conductor assembly into the load housing 6 Make sure the resistor fitting makes...

Page 31: ...for any reason request an RMA through the Bird Technologies website link shown below All instruments returned must be shipped prepaid and to the attention of the RMA number Bird Service Center 30303 Aurora Road Cleveland Solon Ohio 44139 2794 Fax 440 248 5426 E mail bsc bird technologies com For the location of the Sales Office nearest you visit our website at http www bird technologies com ...

Page 32: ...or adapter Operating Position Any Coolant For operation at 1kHz or lower use only distilled water as the coolant For operation at greater than 1kHz use distilled or potable water Coolant Connections standard hose thread barbed hose fitting model 8738A110 Temperature Range 5 to 60 C 41 to 140 F Flow Rate Min 4 gal min 15 2 L min 5 C 41 F 6 gal min 22 7 L min 60 C 140 F Flow Rate Max 12 gal min 45 4...

Page 33: ...8732A 8730A 8738A 1 8732A052 8730A052 8738A053 7 16 Jack IEC Type 169 4 8732A only 1 4240 344 Description Qty Part No Water Chamber Assembly 1 8731 003 Center Conductor Assembly includes resistor 1 8731 005 Outer Conductor Assembly 1 8731 004 Description Qty Part No Hose Connector 2 5A2857 1 Center Conductor Assembly 1 8738A113 Outer Conductor Assembly 1 8738A112 Description Qty Part No Flow Switc...

Page 34: ...uch claim for breach of these war ranties shall be deemed to be waived by Buyer unless made in writing within ten 10 days from the date of discovery of the defect The above warranties shall not extend to any products or parts thereof which have been subjected to any misuse or neglect damaged by accident rendered defective by reason of improper installation or by the performance of repairs or alter...

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