ML-1900 Series 19″ Convection-Cooled 6U 15-Slot Rugged Chassis

Electrical Requirements

  • The chassis shall contain a 750 W power supply. The power supply shall be mounted in such a way that it is field replaceable. The power supply shall operate from an input voltage of 108 – 118 VAC 400 Hz single phase AC power per MIL-STD 704E. The minimum output power shall be as follows:

    +5 VDC at 50 A
    +12 VDC at 4 A
    -12 VDC at 4 A
    -5.2 VDC at 4 A
    The +5 V, +12 V, and the -12 V shall be bussed to the VME card cage per ANSI/IEEE STD 1014-1987. The -5.2 V shall be bussed to a terminal strip that can be accessed by removing the backplane access panel. The -5.2 V terminal strip or connector will be used to distribute -5.2 V to selected through P2.

Mechanical Requirements

  • The overall chassis dimensions shall be as shown in Figure 1.

  • The chassis shall be 19-inch rack mountable in a 9U panel area per EIA RS-310-C. The chassis will mount with standard EIA rack slides (Customer Defined).

  • The VME card cage shall be shock and vibration isolated. It shall have a minimum of 15 (12 for 1″ VPX) positions. The P1 connectors shall be standard VME, they shall be bussed and terminated. The P2 connectors shall be standard VME and shall have row B bussed and terminated. The bottom side of the backplane shall have P2 connectors that will mate a female DIN standard 41612, 96-pin connector.

  • The chassis shall have a drive bay capable of accepting two half-height SAS/SATA canisters. The drives will be accessible through a hinged, EMI-shielded door on the front of the chassis. The drive bay shall be open to the rear to facilitate cabling.

  • The chassis shall be designed with a removable I/O panel on the rear. The panel will be a minimum of 14.75-inches x 3.5-inches.

  • The chassis shall be designed with a protected “On/Off” switch, and a “Power On” indicator on the front panel. The chassis shall also provide circuit breaker protection on the front panel for the AC input power. The circuit breaker shall be capable of withstanding the inrush and steady state current requirements of the power supply.

  • The chassis shall be designed with disk access indicators on the front panel. They will be labeled “D1, D2, D3, D4” as shown in the chassis outline drawing, Figure 1.

  • The chassis shall be designed with integral cooling fans capable of dissipating TBD watts.

  • The chassis shall not exceed 70 lbs.

Environmental Requirements

The chassis shall meet the environment requirements specified herein.

  • The operating range shall be 0 to +50°C. The non-operating temperature range shall be -54° to +65°C.

  • The chassis shall operate in 20 to 90% non-condensing atmosphere.

  • The chassis shall operate over an altitude range of 0 to 10,000 ft. The non-operating altitude range shall be 0 to 30,000 ft.

  • The chassis shall operate without degradation in performance, and shall sustain no physical damage, when subjected to the test of MIL-E-5400 figure 2, sheet 1 curve II.

  • The chassis shall operate without degradation in performance, and shall sustain no physical damage after being subjected to 3 half-sine pulses shocks of 9g, 11 msec. duration each in opposite directions along 3 mutually perpendicular axes for a total of 18 shocks.

  • The mounting surface shall be able to withstand 2 shocks of 9g half-sine, 11 msec. duration each in opposite directions along 3 mutually perpendicular axes for a total of 6 shocks.

  • The sound pressure level generated by the chassis shall not exceed 62 dBa when measured three feet away.

  • The chassis shall be capable of being stored within a protective shelter for up to 30 days. During storage the chassis shall be exposed to temperature extremes ranging from -54° to +65°C. Following storage the chassis shall be capable of operating at rated performance upon return to operating temperatures.

Design and Construction Requirements

  • Materials, components, assembly methods, and finishes to surfaces shall not afford fungus nutrition.

  • Materials which support combustion, or which are capable of causing an explosion, shall be avoided.

  • Materials used shall be of the corrosion-resistant type, or suitably processed or treated to resist corrosion.

  • All parts fabricated from aluminum alloys shall be chemically treated in accordance with MIL-C-5541. Paint shall be TBD.

  • The chassis shall be designed to satisfy the intent of MIL-STD-461 Part II, Category A1b requirements for electromagnetic interference.

  • Dissimilar metals, as defined in MIL-STD-889, shall not be used in contact with each other unless suitably protected against electrolytic corrosion.

  • Items supplied to this drawing shall be identified in accordance with MIL-STD-1258 with the following information as a minimum:

    1. Manufacturer
    2. This drawing number followed by a “-01”
    3. Serial number

Quality Assurance Provisions

  • Unless otherwise specified in the purchase contract, the manufacturer is responsible for the performance of all inspections specified herein. The procuring activity reserves the right to perform any of the inspections deemed necessary to assure that supplies and services conform to the prescribed requirements.

  • The manufacturer shall be responsible for having adequate inspection procedures to guarantee that items procured to this drawing will meet the requirements specified herein.

Preparation for Delivery

  • The items shall be packaged and preserved to assure against damage during shipping and storage.

  • External

    As a minimum, the shipping container shall be marked with the procuring activities name, address, and purchase contract number.


    As a minimum, the internal packages shall be marked with the items listed in Part Marking.


  • Suggested design improvements shall be referred to the procuring activity for review. There shall be no change made in the design or in the materials used in the manufacture of the part covered by this drawing without notification to the procuring activity.

  • When required as part of the procurement package, the following information shall be appropriately referenced on the purchase contract:

    1. This drawing number, title, and date
    2. Test data requirements
    3. Special marking requirements
    4. Special preservation, packaging, and packing requirements
    5. Special sampling plan

Applicable Documents

The following documents apply as specified herein:

ANSI/IEEE STD 1014-1987 VME Bus Specification
MIL-STD-810E Environmental Test Methods and Engineering Guidelines
MIL-STD-454N Standard General Requirements for Electronic Equipment
MIL-STD-704E Aircraft Electric Power Characteristics
MIL-E-5400 Electronic Equipment, Airborne, General Requirements for
MIL-STD-973 Configuration Management
MIL-STD-1472D Human Engineering Design Criteria for Military Systems
MIL-C-5541E Chemical Conversion Coatings on Aluminum and Aluminum Alloys
MIL-STD-889B Dissimilar Metals
EIA RS-310-C EIA Standard Racks Panels and Associated Equipment
MIL-I-45208A Inspection Requirements