SANDIA aerospace MARC-70 User manual

MARC-70 Interface Modules
Simplifying Complex Installations
SANDIA aerospace
PMA Certied
Multiple Modules to Choose From
Certied to 50,000 Feet or Above
Three Enclosures to Fit Every Requirement
Photo Courtesy NASA Hubble

Installation Solutions Modules
MARC 70 Switching and Interface Modules provide system engineers and installers with simple to install,
PMA certied solutions to previously complex installations. MARC 70 modules can be mounted individu-
ally in the SRU 1 or grouped in the SRU 5 and SRU 10 multi-module enclosures. No matter which mounting
method you choose, servicing the module is as easy as pulling one out and inserting another. And as with all
SANDIA aerospace products they are back by a three year no hassle warranty.
Special Interface Modules
SA 3/SA 3L/SA 3NVG
Regulator/Dimming Module
Provide .5 amps of annunciator drive
(1 amp short term for test purposes).
The SA-3 and SA-3Lprovide two lev-
els of brightness for day and night set-
tings. The SA-3 is used with incandes-
cent lamps, the SA-3L is for use with
LED lamps. The SA-3NVG provides
a third level of display brightness for
NVG applications. FAA-PMA
SA 15
Inverter Module
The SA 15 signal inputs in order to
provide common annunciator switch-
ing. The SA 15 has 14 inverter out-
puts. PMA Pending
SA 24
Diode Isolation Module
Provides 23 lines of diode ground-in-
ground-out isolation. Internal FET al-
lows simultaneous test of all lines to
ground. Requires 28Vdc in for test.
FAA-PMA
Choice of Enclosures
SRU 1
Single Card Enclosure SRU 5
Five Card Enclosure SRU 10
Ten Card Enclosure
Mil Qualied Switching Modules
SR 623
The SR263 has two, six pole nitrogen
lled relays. The two relays can be
activated simultaneously or individu-
ally. FAA-PMA
SR 343
The SR 343 has three, four pole nitrogen
lled relays. The three relays can be
activated simultaneously or individu-
ally. FAA-PMA
SR 623
The SR 623 has six, two pole ni-
trogen lled relays. The six relays
are activated individually. FAA-
PMA
GA Switching Modules
SR 34
The SR 34 uses three, four pole sealed
relays to provide 12 lines of switch-
ing. Coil current 60mA. PMA Pend-
ing
SR 54
The SR 54 is a twenty pole relay unit
ideally suited for switching the HSI
between GPS and VOR/LOC func-
tions. Coil Current 120mA. PMA
SR 64
The SR 64 is a multi-purpose relay
module that provides 24 lines of
switching. Coil current 120mA.
FAA-PMA Pending
3700 Osuna Rd. NE
Albuquerque, NM 87109
www.sandia.aero
SANDIA aerospace
R3-0912-1000

MARC70
Installation Manual
SA 3/L/NVG
SA 15
SA 24
305147-00
3700 Osuna Rd. NE, Suite 711
Albuquerque, NM 87109
505.341.2930
www.sandia.aero
SR 34
SR 54
SR 64
SR 263
SR 342
SR 623
SRU 1
SRU 5
SRU 10

Record of Revisions
Revision Date Description Approval
-1 June 25, 2000 Initial Release J. Fiala 000814
-2 March 29, 2001 ECN 3271 J. Fiala 010329
-3 July 16, 2004 ECN 3428 J. Fiala 040716
-4 Sept 26, 2006 ECN 1319 J. Fiala 20060926
-5 June 10, 2010 ECN 3739 L. Harrison 20100610
-6 January 24, 2012 ECN 3866 L. Harrison 20120125
This document and the information contained herein is the proprietary data of SANDIA aerospace,
Inc. No part of this document may be transmitted, reproduced, or copied in any form or by any
means without the prior written consent of SANDIA aerospace, Inc. Due to SANDIA aerospace’s
continued product and quality improvement programs, information contained in this document is
subject to change without prior notice.
Copyright 2000 SANDIA aerospace, Inc., All rights reserved. Printed in USA
Page 1
305147-00

Table Of Contents
Record of Revisions .............................................................1
Table of Contents ...............................................................2
List of Illustrations ..............................................................3
Section 1 - General Description ....................................................4
1.1 Introduction .............................................................4
1.1.1 Interface Modules..................................................4
1.1.2 Card Enclosures ...................................................4
1.1.3 SRU 1 ...........................................................4
1.1.4 SRU 5 ...........................................................5
1.1.5 SRU 10 ..........................................................5
1.2 Technical Characteristics ...................................................5
1.2.1 Physical Characteristics..............................................5
1.2.2 Operational Characteristics ...........................................6
 1.2.3 Certication .......................................................6
 EnvironmentalQualicationForm(SA3,SA15,SA24,SR263,SR343,SR623) .......7
 EnvironmentalQualicationForm(SR34,SR54,SR64) ..........................8
 EnvrionmentalQualicationForm,SA3NVG ..................................9
Section - 2 Installation .........................................................10
2.1 Introduction ............................................................10
2.2 Mounting Considerations..................................................10
2.3 Cooling................................................................10
Section - 3 Installation Procedures ................................................10
3.1 General................................................................10
3.2 Mounting Instructions ....................................................10
3.2.1 SRU 1 Outline Dimensions ..........................................11
3.2.2 SRU 5 Mounting Instructions ........................................12
3.2.2.1 SRU 5 Outline Dimensions ......................................12
3.2.3 SRU 10 Mounting Instructions .......................................12
3.2.3.1 SRU 10 Outline Dimensions .....................................12
3.3 Interconnect Wiring ......................................................14
3.3.1 SA 3/SA3L, Regulator / Dimming Module .............................14
 3.3.2 SA3NVGRegulator/DimmingModule ...............................14
3.3.3 SA 15, Inverter Module ............................................14
3.3.4 SA 24, Diode Isolation / Test Module..................................15
3.3.5 SR 34, 12 Pole Switching Module ....................................15
3.3.6 SR 54, 20 Pole Switching Module ....................................15
3.3.7 SR 64, 24 Pole Switching Module ....................................15
3.3.8 SR 263, 12 Pole Switching Module ...................................16
3.3.9 SR 343, 12 Pole Switching Module ...................................16
3.3.10 SR 623, 12 Pole Switching Module ...................................16
SA 3 / SA 3L Schematic and Pinout.....................................17
  SA3NVGSchematicandPinout .......................................18
SA 15 Schematic and Pinout ..........................................18
SA 24 Schematic and Pinout ..........................................19
SR 34 & SR 64 Schematic and Pinout...........................................20
SR 54 Schematic and Pinout ..........................................21
SR 263 Schematic and Pinout .........................................22
SR 343 Schematic and Pinout .........................................23
SR 623 Schematic and Pinout .........................................24
Page 2

List of Illustrations
Figure 3-1 SRU 1 Outline Dimensions ...................................11
Figure 3-2 SRU 5 / SRU 5-01 Outline Dimensions ..........................12
Figure 3-3 SRU 10 Outline Dimension ...................................13
Figure 3-4 SA 3 / SA 2L Schematic and Pinout .............................17
Figure3-5 SA3NVGSchematicandPinout ...............................18
Figure 3-6 SA 15 Schematic and Pinout...................................19
Figure 3-7 SA 24 Schematic and Pinout...................................20
Figure 3-8 SR 34 and SR 64 Schematic and Pinout .........................21
Figure 3-9 SR 54 Schematic and Pinout...................................22
Figure 3-10 SR 263 Schematic and Pinout..................................23
Figure 3-11 SR 343 Schematic and Pinout..................................24
Figure 3-12 SR 623 Schematic and Pinout..................................25
Figure 3-13 SA 3 / SA 3LAdjustment Locations.............................26
Figure3-14 SA3NVGAdjustmentLocations ...............................26
Page 3
305147-00
3.4 Calibration Procedures....................................................25
3.4.1 SA 3 / SA 3L.....................................................26
 3.4.2 SA3NVG .......................................................26
3.5 Continued Airworthiness ..................................................27
Table Of Contents con’t

Section 1 General Description
1.1 Introduction
This manual describes the installation of the SANDIA aerospace MARC70 line of interface mod-
ules.ItisintendedforusebyFAAcertiedrepairstationstoinstalltheMARC70modules.It
includes both the mechanical and electrical installation information for all MARC70 components,
including the individual modules and enclosures. Where applicable, alignment and checkout proce-
dures are included. In many instances, such as with switching relays, the checkout procedure will be
performedaspartofthemajorsysteminstallationcheckoutandnospeciccheckoutprocedureis
provided for in this manual. In any case, the installer should insure that all functions are operating
according to their intended purpose in their particular installation.
1.1.1 Interface Modules
All interface modules have the same mechanical dimensions and are inserted into the card enclosures
inthesamemanner.Anidenticationtagaccompanieseachinterfacemodulewhichshouldbeat-
tached to the card enclosure directly above the interface module to identify it. Each interface module
connectors, except the SR 34, SR 54 and SR 64, is keyed to prevent the inadvertent installation of
the connector into the wrong module. Keying of the module has been accomplished at the factory by
the removal of one of the pins on the module’s connector. The installing agency MUST insert a key-
ing plug into the appropriate pin location on the harness connector to complete the keying process.
Each MARC70 interface module is FAA-PMA approved and has been tested to meet the require-
ments necessary to allow it to be mounted outside the aircraft’s pressure vessel. Each interface mod-
ule has passed the vibration requirements for helicopter installations. See section 1-2 for complete
technicalspecicationoneachoftheMARC70modules.
1.1.2 Card Enclosures
Several different card enclosures are available depending on the application and installation space
available.Ifanenclosureisnotlled,theunusedcardslotsarecoveredwithblankpanels.These
extra card slots can be used in future installations or system upgrades, eliminating the need to re-
engineer the mechanical installation. Interface modules are secured to the enclosures with captive
stainlesssteelscrews.Ininstallationswheretheenclosureisdifculttoreach,theharnessconnector
canbeattachedrstthenthemoduleinsertedintotheappropriatecardslotandsecuredwiththecap-
tive hold down screws.
1.1.3 SRU-1
The SRU 1 is a single card enclosure which accepts any MARC70 interface module. The SRU 1 is
ideally suited for installations where only one MARC70 card is required or where there is limited
real estate for mounting the larger enclosures. The SRU 1 can be mounted in any axis and either
inside or outside the pressure vessel.
1.1.4 SRU 5
Page 4

TheSRU5isamulti-cardenclosurethatacceptsuptoveMARC70interfacemodules.TheSRU
5canbemountedeitherinsideoroutsidethepressurevessel.Whenlessthanveinterfacemodules
are used with the SRU 5, cover plates are placed over the unused card slots. If additional cards are
required at a later date, the cover plates can be removed and the appropriate interface card installed.
When installing the SRU 5 ample room should be allowed for both connector clearance and for
inserting and removing the interface modules. The SRU 5 as well as the interface modules can be
mounted in any axis.
1.1.5 SRU 10
The SRU 10 is multi-card enclosure that accepts up to ten MARC70 interface modules. It is ideally
suitedforinstallationsthatwillrequiremorethanveinterfacemodules.AswiththeSRU5,un-
used slots are covered with cover plates included in the installation kit. These extra slots can be used
on future installations, eliminating the need for additional mechanical engineering and approval.
The SRU 10 can be installed either inside or outside the aircraft’s pressure vessel. For installation
exibility,theSRU10andtheinstalledinterfacemodulescanbemountedinanyaxis.Ampleroom
should be allowed for both the connector and for inserting and removing the interface modules.
1.2 TECHNICAL CHARACTERISTICS
The conditions and tests performed for FAA-PMA approval of these articles are minimum perfor-
mance standards. It is the responsibility of the installing agency to determine that the aircraft operat-
ing conditions are within these FAA-PMA parameters.
1.2.1 Physical Characteristics
* With Module Installed
Page 5305147-00
Unit Part Number Width Height Depth Weight
SA 3 305005-01 3.92 in. 3.5 in. .82 in. .20 lb
SA 3L 305005-02 3.92 in. 3.5 in. .82 in. .20 lb
SA3NVG 306070-00 3.92 in. 3.5 in. .82 in. .29 lb
SA 15 305004-01 3.92 in. 3.5 in. .82 in. .15 lb
SA 24 305003-01 3.92 in. 3.5 in. .82 in. .18 lb
SR 34 305501-00 3.92 in. 3.5 in. .82 in. .19 lb
SR 54 305498-00 3.92 in. 3.5 in. .82 in. .26 lb
SR 64 305499-00 3.92 in. 3.5 in. .82 in. .25 lb
SR 263 305001-01 3.92 in. 3.5 in. .82 in. .16 lb
SR343 305000-01 3.92 in. 3.5 in. .82 in. .18 lb
SR 623 305002-01 3.92 in. 3.5 in. .82 in. .24 lb
SRU 1 305146-00 5.2 in. 1.0 in. 3.9 in.* .37 lb
SRU 1-01 305146-01 5.2 in. 1.0 in 3.9 in. * .37 lb
SRU 5 305018-00 5.4 in. 4.0 in. 3.65 in. * .80 lb
SRU 10 305014-00 9.55 in. 4.0 in. 3.65 in. * 1.32 lb

1.2.2 Operational Characteristics
1.2.3 Certication
Page 6
* SA3 PMA’d with SRU1 as SAS 1-3
** SA24 PMA’d with SRU 1 as SAS 1-24
Unit Part Number Operating Temp Altitude Voltage Current Req.
SA 3 305005-01 -55oto +70o C 70,000 Ft. 28Vdc
SA 3L 305005-02 -55oto +70o C 70,000 Ft. 28Vdc
SA3NVG 306070-00 -55oto +70o C 35,000 Ft. 28Vdc
SA 15 305004-01 -55oto +70o C 70,000 Ft. N/A N/A
SA 24 305003-01 -55oto +70o C 70,000 Ft. N/A .003Amp
SR 34 305501-00 -20oto +55oC 50,000 Ft. 28Vdc 60mA
SR 54 305498-00 -20oto +55oC 50,000 Ft. 28Vdc 120mA
SR 64 305499-00 -20oto +55oC 50,000 Ft. 28Vdc 120mA
SR 263 305001-01 -55oto +70o C 70,000 Ft. 28Vdc 150mA
SR 343 305000-01 -55oto +70o C 70,000 Ft. 28Vdc 220mA
SR 623 305002-01 -55oto +70o C 70,000 Ft. 28Vdc 250mA
SRU 1 305146-00 -55oto +70o C 70,000 Ft. N/A N/A
SRU 5 305018-00 -55oto +70o C 70,000 Ft. N/A N/A
SRU 5-01 305018-01 -55oto +70o C 70,000 Ft. N/A N/A
SRU 10 305014-00 -55oto +70o C 70,000 Ft. N/A N/A
Unit Part Number PMA STC Aircraft
SA 3 305005-01 Yes
Yes* ST09475SC ST3007WI-T Embraer EMB120 Cessna Citation 650
SA 3L 305005-02 No
SA3NVG 306070-00 Pending Pending Eurocopter BK-117-C2
SA 15 305004-01 Pending
SA 24 305003-01 Yes** ST09475SC Embraer EMB120
SR 34 305501-00 Pending
SR 54 305498-00 Pending
SR 64 305499-00 Pending
SR 263 305001-01 Yes ST00318DE-D Learjet 55
SR 343 305000-01 Yes ST00318DE-D Learjet 55
SR 623 305002-01 Yes ST3007WI-T Cessna Citation 650
SRU 1 305146-00 Yes*/** ST09475SC Embraer EMB 120
SRU 5 305018-00 Yes ST3007WI-T Cessna Citation 650
SRU 5-01 305018-01 Eurocopter BK-117-C2
SRU 10 305014-00

SA 3, SA 15, SA 24, SR263, SR 343, SR 623
EnvironmentalQualicationForm
Page 7305147-00
NOMENCLATURE: MARC70 RELAY, DIODE ISOLATOR,INVERTER AND REGULATOR UNIT
TYPE/MODEL/PART NO: MARC70/SA3, SA15, SA54, SR263, SR343, SR623
TSO NUMBER: DO160Env. Cat.E1-BBA[(SBL09U)]XXXXXXZZAZZULXXX
MANUFACTURER’S SPECIFICATION AND/OR OTHER APPLICABLE SPECIFICATIONS:
MARC70 INSTALLATION MANUAL 305147-00
ENVIRONMENTAL TEST PLAN SR343, SR263, SR623, SA24, SA15, SA3 Doc # MK700020
MANUFACTURER: SANDIA AEROSPACE
ADDRESS: 3700 OSUNA RD NE, STE 711, ALBUQUERQUE, NM 87109
REVISION & CHANGE NUMBER OF DO-160: REV D. DATED JULY 27, 1997
CONDITION SECTION DESCRIPTION OF TESTS CONDUCTED
Temperature and Altitude
Low Temperature
High Temperature
In-ightLossofCooling
Altitude
Decompression
Overpressure
4.0
4.5.1
4.5.2 & 4.5.3
4.54
4.6.1
4.6.2
4.6.3
Equipment tested to category E1
Tested to +70oC Operating High Temperature
Tested to +85oC Ground Survival
Test not Applicable
70,000 feet
Test not Applicable
Test not Applicable
TemperatureVariation 5.0 Tested to Category B
Humidity 6.0 Tested to Category B
Operational Shock and Crash Safety 7.0 Tested to Category A, Aircraft Type 5. Random Orientation
Vibration 8.0 Tested to Category S, Aircraft Zone 2 using vibration curves B and
M.
Tested to Category U, Helicopter Zone 2 using vibration curves F and
F1.
Explosion 9.0 EquipmentidentiedasCategoryX,notestperformed
Waterproofness 10.0 TestedtoCategoryX,notestperformed
Fluids Susceptibility 11.0 EquipmentidentiedasCategoryX,notestperformed
Sand and Dust 12.0 EquipmentidentiedasCategoryX,notestperformed
Fungus 13.0 EquipmentidentiedasCategoryX,notestperformed
Salt Spray 14.0 EquipmentidentiedasCategoryX,notestperformed
Magnetic Effect 15.0 Equipment is Category Z
Power Input 16.0 Tested to Category Z
VoltageSpike 17.0 Tested to Category A
Audio Frequency Susceptibility 18.0 Tested to Category Z
Induced Signal Susceptibility 19.0 Tested to Category Z
Radio Frequency Susceptibility 20.0 Tested to Category U
Radio Frequency Emission 21.0 Tested to Category L
Lightning Induced Transient
Susceptibility 22.0 TestedtoCategoryX,notestperformed
Lightning Direct Effects 23.00 EquipmentidentiedasCategoryX,notestperformed
Icing 24.0 EquipmentidentiedasCategoryX,notestperformed
Electrostatic Discharge 25.0 EquipmentidentiedasCategoryX,notestperformed

SR 34, SR 54, SR 64
EnvironmentalQualicationForm
Page 8
NOMENCLATURE: MARC70 RELAY
TYPE/MODEL/PART NO: MARC70/SR34, SR54, SR64
TSO NUMBER: DO160Env. Cat.[A1D1]-CA9MN0XXXXXXZBABATZXXX
MANUFACTURER’S SPECIFICATION AND/OR OTHER APPLICABLE SPECIFICATIONS:
MARC70 INSTALLATION MANUAL 305147-00
MANUFACTURER: SANDIA AEROSPACE
ADDRESS: 3700 OSUNA RD NE, STE 711, ALBUQUERQUE, NM 87109
CONDITION SECTION DESCRIPTION OF TESTS CONDUCTED
Temperature and Altitude
Low Temperature
High Temperature
In-ightLossofCooling
Altitude
Decompression
Overpressure
4.0
4.5.1
4.5.2 & 4.5.3
4.54
4.6.1
4.6.2
4.6.3
Equipment tested to category A1 & D1
Tested to -20oC Operating Low Temperature
Tested to -55oC Ground Survival
Tested to +70oC Operating High Temperature
Tested to +85oC Ground Survival
Test not Applicable
50,000 feet
50,000 feet
-15,000 feet
TemperatureVariation 5.0 Tested to Category C
Humidity 6.0 Tested to Category A
Operational Shock and Crash Safety 7.0 Operational to Para. 7.2.1
CrashsafetytoPara.7.3.1(impulse)
Vibration 8.0 Tested to Category M & N
Explosion 9.0 EquipmentidentiedasCategoryX,notestperformed
Waterproofness 10.0 TestedtoCategoryX,notestperformed
Fluids Susceptibility 11.0 EquipmentidentiedasCategoryX,notestperformed
Sand and Dust 12.0 EquipmentidentiedasCategoryX,notestperformed
Fungus 13.0 EquipmentidentiedasCategoryX,notestperformed
Salt Spray 14.0 EquipmentidentiedasCategoryX,notestperformed
Magnetic Effect 15.0 Equipment is Category Z
Power Input 16.0 Tested to Category B
VoltageSpike 17.0 Tested to Category A
Audio Frequency Susceptibility 18.0 Tested to Category B
Induced Signal Susceptibility 19.0 Tested to Category A
Radio Frequency Susceptibility 20.0 Tested to Category T
Radio Frequency Emission 21.0 Tested to Category Z
Lightning Induced Transient
Susceptibility 22.0 TestedtoCategoryX,notestperformed
Lightning Direct Effects 23.00 EquipmentidentiedasCategoryX,notestperformed
Icing 24.0 EquipmentidentiedasCategoryX,notestperformed
REVISION & CHANGE NUMBER OF DO-160: REV D. DATED JULY 27, 1997

Page 9
NOMENCLATURE: SA 3 NVG DIMMER W?PLATE SRU5
TYPE/MODEL/PART NO: SA 3 NVG / 306070-[XX]
SRU 5 NVG / 305018-[XX]
TSO NUMBER: DO160Env. Cat. [C2X]BBA[(SBM)(UG)]XXXXXXZZAZ[ZC][SS]LXXXXX
MANUFACTURER’S SPECIFICATION AND/OR OTHER APPLICABLE SPECIFICATIONS:
MARC70 INSTALLATION MANUAL 305147-00
ENVIRONMENTAL TEST PLAN: 901073-QTP, QTP, SA 3 NVG DIMMER
MANUFACTURER: SANDIA AEROSPACE
ADDRESS: 3700 OSUNA RD NE, STE 711, ALBUQUERQUE, NM 87109
CONDITION SECTION DESCRIPTION OF TESTS CONDUCTED
Temperature and Altitude
Low Temperature
High Temperature
In-ightLossofCooling
Altitude
Decompression
Overpressure
4.0
4.5.1
4.5.2
4.5.3
4.5.4
4.5.5
4.6.1
4.6.2
4.6.3
Equipment tested to category C2
-55oC Ground Survival / -55oShort
-55o Operating
+85oC Ground Survival / + 70oShort
+70oC Operating High Temperature
Not Applicable
35,000 feet
N/A
N/A
TemperatureVariation 5.0 Tested to Category B
Humidity 6.0 Tested to Category B
Operational Shock and Crash Safety 7.0 Tested to Category A
Vibration 8.0 Tested to Category S Curves B and M
Tested to Category U, Curve G
Explosion 9.0 EquipmentidentiedasCategoryX,notestperformed
Waterproofness 10.0 TestedtoCategoryX,notestperformed
Fluids Susceptibility 11.0 EquipmentidentiedasCategoryX,notestperformed
Sand and Dust 12.0 EquipmentidentiedasCategoryX,notestperformed
Fungus 13.0 EquipmentidentiedasCategoryX,notestperformed
Salt Spray 14.0 EquipmentidentiedasCategoryX,notestperformed
Magnetic Effect 15.0 Equipment is Category Z
Power Input 16.0 Tested to Category Z
VoltageSpike 17.0 Tested to Category A
Audio Frequency Susceptibility 18.0 Tested to Category Z
Induced Signal Susceptibility 19.0 Tested to Category [ZC]
Radio Frequency Susceptibility 20.0 Tested to Category S
Radio Frequency Emission 21.0 Tested to Category L
Lightning Induced Transient Suscep-
tibility 22.0 TestedtoCategoryX,notestperformed
Lightning Direct Effects 23.0 EquipmentidentiedasCategoryX,notestperformed
Icing 24.0 EquipmentidentiedasCategoryX,notestperformed
Electrostatic Discharge 25.0 EquipmentidentiedasCategoryX,notestperformed
Fire, Flammability 26.0 EquipmentidentiedasCategoryX,notestperformed
SA3NVG
EnvironmentalQualicationForm

2.2 Mounting Considerations
The MARC70 family of interface modules and their associated mounting enclosures can
be mounted in any attitude and either inside or outside the pressure vessel. Each card is
installed in the desired mounting enclosure by inserting it into a vacant location and secur-
ing it with the two stainless steel fasteners attached to the modules front plate. The interface
modules can only be inserted and secured in one direction. While the modules are relatively
easy to install and remove in the enclosures, considerations should be given to service access.
At least six inches of clearance should be provided at the front of the enclosures for removal
and reinsertion of MARC70 modules It is also recommended that enough cable be supplied
so that the interface modules can be inserted and removed with the cable harness and connec-
tor attached to the module. This will aid in any calibration that may be required and will also
simplify attaching the connector to the interface module.
.
2.3 Cooling
Cooling for the MARC70 is not required. However if several higher current modules, such
as annunciator drivers are installed, adequate space should be allowed for convection cool-
ing.TheSA3NVGmustbemountedintherightmostslotoftheSRU-5-01,PN305018-
01and secured with two screws supplied with the unit.
Section 3 Installation Procedures
3.1 General
Each MARC70 module is supplied with a mating connector, crimp style pins and an indenti-
cationtag.Theidenticationtagistobeplacedonthetopoftheenclosuredirectlyoverthe
slot in which the module is installed. The enclosures are supplied with enough blank plates
and screws to cover any unused slots. Extra blank plates and screws can be discarded or
retained in case a module is ever removed.
3.2 Mounting Instructions
The SRU 1 is attached to an aircraft structure by using four #10-32 screws as shown in the
outline drawing.
Section 2 Installation
2.1 Introduction
The MARC70 family of enclosures and interface modules has been designed to simplify and
standardize installation of avionics systems. SANDIA aerospace supplies each mounting
enclosure and interface module separately. The installer can mix and match the modules in
theenclosurestomeetspecicrequirements.ExceptfortheSR34,SR54andSR64,each
of the module’s connectors is keyed to prevent inadvertently attaching the wrong connector.
It is important that the installer insert the supplied plug in the proper location in the mating
connector for the keying to be complete.
305147-00 Page 10

Page 11
3.2.1 SRU 1 Outline Dimensions
Figure 3-1
SRU 1 Outline Dimensions

305147-00
3.2.2 SRU 5 Mounting Instructions
The SRU 5 is attached to an aircraft structure by using four #10-32 screws as shown in the
outline drawing.
3.2.2.1 SRU 5 & SRU 5-01 Outline Dimensions
TopView
FrontView
SideView
Figure 3-2
SRU 5 & SRU 5-01 Outline Dimensions
Page 12

3.2.3 SRU 10 Mounting Instructions
The SRU 10 is attached to an aircraft structure by using four #10-32 screws as shown in the
outline drawing.
3.2.3.1 SRU 10 Outline Dimensions
Page 13
TopView
FrontViewSideView
Figure 3-3
SRU 10 Outline Dimensions

3.3 Interconnect Wiring
The SA 3 & 3L Regulator/ Dimming Modules provide a source of power to drive up to .5
amps of continuous current for aircraft annunciators. The SA 3 & 3L will provide 1 amp
short term for testing of annunciators. Aircraft power is supplied to 7 pins for installation
exibility.TwoadjustmentsallowsettingtheHighandLowintensityoftheannunciatorsto
match existing aircraft annunciators.
Pin 2 on the SA 3 & 3L is the keying pin and has been removed at the factory. A plug which
is supplied with the installation kit must be inserted into Pin 2 of the mating connector.
The SA 3 is for use with incandesent lamps while the SA 3L is for use with LED Lamps.
Seegure3-4foraschematicandpinoutoftheSA3&3L
3.3.3 SA 15 Inverter Module
TheSA15moduleallowsequipmentwith+5Vdcor+28Vdclampoutputstodrivepanel
annunciator lamps that require grounded inputs. The SA 15 inverts up to 14 high level lamp-
driver inputs providing independent low outputs for each line. The 14 inverters are arranged
intwobanksof7invertersforinstallationexibility.Asinglelineoneachinverterbank
allows simultaneous testing of all 7 outputs. The inverters may also be cascaded, providing
consistent drive polarity and simplifying press to test wiring of panel annunciators.
Pin 36 on the SA 15 is the keying pin and has been removed at the factory. A plug which is
supplied with the installation kit must be inserted into Pin 36 of the mating connector.
Seegure3-5foraschematicandpinoutoftheSA15
Page 14305147-00
3.3.2 SA 3 NVG Regulator/ Dimming Module
TheSA3NVGRegulator/DimmingModuleprovideasourceofpowertodriveupto.5amps
ofcontinuouscurrentforaircraftannunciators.TheSA3NVGwillprovide1ampshortterm
fortestingofannunciators.Aircraftpowerissuppliedto7pinsforinstallationexibility.
ThreeadjustmentsallowsettingtheHigh,LowandNVGintensityoftheannunciators.A
groundisappliedtoPin4oftheconnnectorJ1toputtheSA3NVGintheNVGmode.A
groundonJ1Pin3putstheoutputinDim(night)modeandwithbothJ1Pins3and4open
theoutputisintheBright(day)mode.
TheSA3NVGmustbemountedintherightmostslotoftotheSRU5-01SandiaP/N
305018-01 and secured with two 1/2 inch 4-40 screws supplied with the unit. The SRU 5
actsasaheatsinkandshouldnotbemountednearamablesubstances.
Pin2ontheSA3NVGisthekeyingpinandhasbeenremovedatthefactory.Aplugwhichis
supplied with the installation kit must be inserted into Pin 2 of the mating connector.
3.3.1 SA 3 & SA 3L Regulator/ Dimming Modules

3.3.5 SR 34 12 Pole Switching Module
The SR 34 provides 12 poles of switching through three, hermetically sealed, bifurcated re-
lays.Therelayscontactsaregoldplatedandhavea2ampresistiveloadratingat28VDC.
Coil current is 60 mA. Both the SR 34 and SR 64 use the same circuit card. Each relay is
independently switched through their appropriate coil pins.
Seegure3-7foraschematicandpinoutoftheSR34
3.3.6 SR 54 20 Pole Switching Module
3.3.7 SR 64 24 Pole Switching Module
Page 15
TheSR54provides20polesofswitchingthroughve,hermeticallysealed,bifurcatedre-
lays. The SR 54 has a built in circuit that swithces all relays to their de-energized conditon
whenever K6 is activated. This can be used for such applications as insuring LOC is present-
ed on the HSI whenever a LOC signal is selected. The relays contacts are gold plated and
havea2ampresistiveloadratingat28VDC.Coilcurrentis120mA.
Seegure3-8foraschematicandpinoutoftheSR54
The SR 64 provides 24 poles of switching through six, hermetically sealed, bifurcated relays.
Therelayscontactsaregoldplatedandhavea2ampresistiveloadratingat28VDC.Coil
current is 120 mA. K1, K2, K3 and K4 are switched simultaneoulsy through coil pins, 71
and 72. K5 and K6 are independently switched through their coil pins.
Seegure3-7foraschematicandpinoutoftheSR64
CAUTION
Since all pins on the SR 34, SR 54 and SR 64 are used for switching func-
tions, thereis NO KEYING PIN. Cautions must be taken when reattaching
the connector to insure that it is going to the correct devise. Failure to do
so may result in board damage.
3.3.4 SA 24 Diode Isolation/Test Module
The SA 24 provides 23 lines of diode isolation. The SA 24 also provides a test input for
testing annunciators. The test input can be either a high or a low. Pin 48 on the SA 24 is the
keying pin and has been removed at the factory. A plug which is supplied with the installa-
tion kit must be inserted into Pin 48 of the mating connector.

305147-00
3.3.9 SR 343 12 Pole Switching Module
TheSR343provides12polesofrelayswitchingthrough3MILQualied,hermetically
sealed,andnitrogenlledrelays.Therelayscontactsaregoldplatedhardenedsilveralloy
witha2ampresistiveloadcapacityat28Vdc.Eachofthethreerelayscanbeactivatedin-
dependently by supplying switching logic to their coils through pins 38 & 40 for K1, pins 43
& 44 for K2 and pins 48 & 49 for K3. They can also be switched as group by suppling the
switching logic to pins 39 & 45.
Pin 42 on the SR 343 is the keying pin and has been removed at the factory. A plug which is
supplied with the installation kit must be inserted into Pin 42 of the mating connector.
Seegure3-10foraschematicandpinoutoftheSR343
3.3.10SR 623 12 Pole Switching Module
TheSR623provides12polesofswitchingthrough6MILQualied,hermeticallysealed,
andnitrogenlledrelays.Therelayscontactsaregoldplatedhardenedsilveralloywitha
2ampresistiveloadcapacityat28Vdc.Eachofthe6relaysareswitchedindependentlyor
can be switched in any combination by supplying common switching logic to their respective
coils.
Pin 39 on the SR 623 is the keying pin and has been removed at the factory. A plug which is
supplied with the installation kit must be inserted into Pin 39 of the mating connector.
Page 16
TheSR263provides12polesofswitchingthroughtwoMILQualied,hermeticallysealed,
andnitrogenlledrelays.Therelayscontactsaregoldplatedhardenedsilveralloywitha2
ampresistiveloadcapacityat28Vdc.Coilpoweris2.6wattsmax.at25degreesC.
Each relay can be activated independently by supplying the switching logic to their coil
through pins 38 & 40 for K1 and 43 & 44 for K2. Or they can be switched as a pair by sup-
plying the switching logic to pins 39 & 45.
Pin 46 on the SR 263 is the keying pin and has been removed at the factory. A plug which is
supplied with the installation kit must be inserted into Pin 46 of the mating connector.
Seegure3-9foraschematicandpinoutoftheSR263
3.3.8 SR 263 12 Pole Switching Module

Figure 3-4
SA 3/SA 3L Schematic and Pinout
Page 17