An Integrated Publishing, Inc. Site

An Integrated Publishing Website

MIL-PRF-17773 Switches, Bus Transfer, Electric Power Automatic And ManualThis specification covers the Automatic Bus Transfer Switch \(ABT\) \(see 6.4.1\) and the Manual Bus Transfer Switch \(MBT\) \(see 6.4.13\), herein referred to as ABT, MBT, or switch\(es\), for use on surface and submarine Naval vessels. Unless otherwise specified herein, this specification applies to both ABTs and MBTs. Requirements for Static or Solid State ABTs \(SABTs\) are not defined in this specification. MIL-PRF-32150 specifies requirements for SABTs.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16

MIL-PRF-17773C(SH)

TABLE VII. Bus transfer switch short-circuit withstandability.

Short-Circuit

Duration

Current (A)

(seconds)

Continuous Rating (A)

at pf 0.15-0.20

60 Hz

400 Hz

60 Hz

400 Hz

To 50

10000

0.017

0.021

100

15000

10000

.017

.021

250

20000

10000

.025

.028

400

30000

10000

.028

.033

600

50000

10000

.028

.033

Over 600 1/

Note:

1/ Special short-circuit withstandability requirements shall be as

specified (see 6.2).

3.4.40 Dielectric withstanding voltage. Switches shall meet the dielectric withstanding voltage requirements

when tested in accordance with MIL-E-917.

3.4.41 Enclosures. Enclosures for the switch shall be drip-proof, watertight, splash-proof, or open-mounted as

specified (see 6.2) and shall meet the performance requirements of MIL-E-2036 for Class I enclosures for electronic

equipment.

3.5 Environmental conditions.

3.5.1 Ambient temperature. Switches shall operate over an ambient temperature range of 32 to 122 �F (0 to

50 �C) in accordance with MIL-E-917.

3.5.2 Humidity. Switches shall operate in a 95 percent relative humidity environment in accordance with MIL-

E-917.

3.5.3 Pressure. Switches shall operate within performance limits of MIL-STD-202 while subjected to an

atmospheric pressure from 24 to 36 inches of mercury.

3.5.4 Temperature rise. Switches shall operate in an ambient temperature of 122 �F (50 �C) with no more than

a 59 �F (15 �C) temperature rise for surface ships and a 77 �F (25 �C) rise for submarines as specified in MIL-DTL-

16036.

3.5.5 Inclined operation. Switches shall perform satisfactorily during inclined operation as specified in MIL-E-

917.

3.5.6 Shock. Switches shall meet Grade A, Class I, Type A high impact shock tests as specified in MIL-S-901.

3.5.7 Vibration. Switches shall meet Type I vibration tests specified in MIL-STD-167-1.

3.5.8 Protection against arcs. The interior of enclosing cases shall be protected by insulating material selected

in accordance with the requirements of MIL-E-917.

3.5.9 Airborne noise. When specified (see 6.2), airborne noise requirements shall be in accordance with MIL-

STD-1474 unless otherwise specified in 6.2.

3.5.10 Structureborne noise. When specified (see 6.2), structureborne noise requirements shall be in

accordance with MIL-STD-740-2 unless otherwise specified in 6.2.