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INSTALLATION MANUAL AND

 

OPERATING INSTRUCTIONS

 

 

MD41-244/248   RELAY UNIT 

 

MD41-244 

14vdc 

24 Pole, 14 volt operation 

MD41-248 

28vdc 

24 pole, 28 volt operation 

 

 

 

 
 

 

 
 
 
Mid-Continent Instruments and Avionics 

Manual Number 7019029   

9400 E. 34

th

 Street N., Wichita, KS  67226 USA 

Rev. C  Oct. 12, 2020    

Phone 316-630-0101 

 Fax 316-630-0723   

 

 

 

Summary of Contents for MD41-244

Page 1: ...4 248 RELAY UNIT MD41 244 14vdc 24 Pole 14 volt operation MD41 248 28vdc 24 pole 28 volt operation Mid Continent Instruments and Avionics Manual Number 7019029 9400 E 34th Street N Wichita KS 67226 USA Rev C Oct 12 2020 Phone 316 630 0101 Fax 316 630 0723 ...

Page 2: ... B 5566 B 03 09 11 Revised Sec 1 1 1 2 4 to indicate relay pairing and interlock failure monitoring by means of power being applied to activating coils Added section 2 4 Limitations to describe MOD 0 MOD 1 Revised Fig 3 3 to reflect MOD 1 schematic 7283 C 10 12 20 Deleted marketing statement in Sec 1 1 Updated trademark symbol on cover page edited spelling added to footer ...

Page 3: ...CTION 2 INSTALLATION CONSIDERATIONS 2 1 COOLING 2 2 EQUIPMENT LOCATION 2 3 ROUTING OF CABLES 2 4 LIMITATIONS SECTION 3 INSTALLATION PROCEDURE 3 1 GENERAL INFORMATION 3 2 UNPACKING AND INSPECTING 3 3 MOUNTING THE MD41 244 248 3 4 INSTALLATION LIMITATIONS SECTION 4 POST INSTALLATION CHECKOUT 4 1 PRE INSTALLATION TEST 4 2 OPERATING INSTRUCTIONS FIGURE N0 LIST OF ILLUSTRATIONS 3 1A B C OUTLINE DRAWING...

Page 4: ... as a group by ground keying Other design features include Interlocking of transfer relays utilizing one pole per relay pair for failure monitoring This feature provides indication that all relays have power applied to their activating coils It does not monitor all relay contacts or coils A special ILS override that will automatically force the MD41 244 248 to switch to NAV mode when the NAV VOR r...

Page 5: ...ay contact current rating 2 amps DC not to exceed 30 volts 1 2 4 INTERFACE ILS Override Receives a logic low from the NAV VOR J1 Pin 16 receiver when tuned to an ILS frequency This will force the MD41 244 248 into NAV mode regardless of the NAV GPS selection This connection is optional Dimming Output Provides an adjustable dim voltage to be used J2 Pin 33 with a remote mounted annunciation unit 75...

Page 6: ...ion by the applicant documents an acceptable installation and is approved by the Administrator The MD41 244 248 relay unit MUST be installed with a TSO approved MD41 1XXX series Annunciation Control Unit ACU in order to be approved as a complete TSO system These items will not be TSO d if one is installed without the other NOTE Any time the MD41 244 248 relay transfer unit is disconnected or remov...

Page 7: ...nated as the MD41 244 248 Relay Unit This has allowed for a smaller size ACU which now provides more options for panel mounting 2 3 ROUTING OF CABLES Care must be taken not to bundle the MD41 244 248 logic and low level signal lines with any high energy sources Examples of these sources include 400 HZ AC Comm DME HF and transponder transmitter coax Always use shielded wire when shown on the instal...

Page 8: ...ion Manual this document MCIA PN 7019029 Optional parts Mounting brackets for rear mount MCIA PN 8012379 2 required 3 3 MOUNTING THE MD41 244 248 The MD41 244 248 is provided with mounting rails that will allow mounting on the side rear or with flat side down Locate an area large enough to facilitate mounting of unit with connector and back shell in place Ensure area is clear of mechanical obstruc...

Page 9: ...Manual Number 7019029 9 Rev C Oct 12 2020 FIGURE 3 1A OUTLINE DRAWING VERTICAL MOUNT ...

Page 10: ...Manual Number 7019029 10 Rev C Oct 12 2020 FIGURE 3 1B OUTLINE DRAWING HORIZONTAL MOUNT ...

Page 11: ...Manual Number 7019029 11 Rev C Oct 12 2020 FIGURE 3 1C OUTLINE DRAWING REAR MOUNT ...

Page 12: ...Manual Number 7019029 12 Rev C Oct 12 2020 FIGURE 3 2 MATING CONNECTOR LAYOUT ...

Page 13: ...Manual Number 7019029 13 Rev C Oct 12 2020 FIGURE 3 3 SCHEMATIC DIAGRAM MD41 244 248 24 POLE RELAY UNIT ...

Page 14: ...alent VOR signal verify that the presentation and operation of the HSI CDI is correct This will include Course Resolver Left Right meter To From meter and NAV warn flag Now select GPS on the MD41 244 248 and tune the VOR receiver to an ILS frequency The MD41 244 248 will be forced to NAV mode and ILS information will be displayed on the HSI CDI NOTE This feature will not work if ILS Energize J1 pi...

Page 15: ... Altitude Decompression Overpressure 4 0 4 5 1 4 5 2 4 5 3 4 5 4 4 6 1 4 6 2 4 6 3 Equipment tested to Categories A1 F2 except as noted Cooling air not required Not tested Temperature Variation 5 0 Equipment tested to Category B Humidity 6 0 Equipment tested to Category A Shock Operational Crash Safety 7 0 7 2 7 3 Equipment tested per DO 160C Par 7 2 1 Vibration 8 0 Equipment tested without shockm...

Page 16: ...6 0 Equipment tested to Category B Voltage Spike 17 0 Equipment tested to Category A Audio Frequency Susceptibility 18 0 Equipment tested to Category B Induced Signal Susceptibility 19 0 Equipment tested to Category A Radio Frequency Susceptibility 20 0 Equipment tested to Category T Radio Frequency Emissions 21 0 Equipment tested to Category Z Lightning Induced Transient Susceptibility 22 0 Equip...

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