MICRO SWITCH™
Hermetic Sealed Basic Switches
HM Series
Datasheet
MICRO SWITCH™ HM Series
Hermetic Sealed Basic Switches
Honeywell HM hermetic sealed miniature basic switches are designed for a variety of commercial and military aircraft
as well as equipment for deep space applications (high altitude requirements). These miniature hermetic sealed
switches can be found in a variety of other applications including military land vehicles, marine environments, and
other harsh industrial environments. The switches are available as a MIL-PRF-8805 qualified switch. Select HM
switches are available with UL 508 certification for industrial or surface transportation applications. The MICRO
SWITCH™ HM hermetic sealed switch design incorporates the glass-to-metal and metal-to-metal sealing with more
than 50 years of use in multiple applications.
The hermetically sealed HM basic switches are ideal where a symbol 5 seal is required for stringent applications
including a wide range of temperatures from -184 °C to 260 °C [-300 °F to 500 °F]. Designed with a stainless steel
housing and hermetic seal construction, the HM switches are suitable for applications where dust, water, other
particulate contaminants, and corrosive gases are present.
The HM basic switch provides versatility with bifurcated gold contacts for controlling low energy loads (mA and mV)
reliably or silver contacts for switching power duty loads at 30 vdc or 115 Vac, 400 Hz. Electrical connectivity to the
switch is achieved with individual wire leads or “through hole” solder posts adding to the versatility of the HM switch.
What makes our switches better?
Precisely detects position of mechanical components within
a particular system that is susceptible to physical and atmo-
spheric (corrosive gas, oxygen, etc.) elements
Consistent and precise performance in a hermetic-sealed
package for adverse, inclement environments
Functionality over a large temperature range – can tolerate
very low and high temperatures
Honeywell can create value-added HM assemblies for
unique, custom applications beyond a simple HM switch
HM switches are available with MIL-PRF-8805 qualifications
or UL 508 certifications
HM Series: when you need a
switch with out-of-this-world
performance!
HIGH PERFORMANCE • DURABILITY
CONFIGURABLE • COMPACT
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Features
and Benefits
MIL-QUALIFIED
MICRO SWITCH™ HM switches are
hermetically sealed
with versions that are
MIL-PRF-8805
qualified for demanding military or commercial applications on
aircraft, spacecraft, or ground vehicles.
UL CERTIFIED
Select HM catalog listings are
UL 508 certified
for industrial and surface
transportation applications.
TINY
Miniature package size
requires minimal space on equipment.
Hermetically sealed with wide temperature range
SEALED TIGHT
HM Series’
Symbol 5
hermetic-sealed enclosures are suitable for applications at
sea level, high altitude, or deep space.
LOW VOLTAGE AND POWER DUTY CAPABILITY
MICRO SWITCH™ HM products are available with
silver contacts
for control of
power duty circuits or
gold contact surfaces
for control of logic level circuits.
LEVERS FURTHER EXPAND FUNCTIONALITY
Auxiliary actuators
expand the versatility of the switch for additional applications.
WELL SUITED FOR LOW AND HIGH TEMPERATURES
For endurance in harsh temperature environments,
wide temperature range
is available from -184 °C to 260 °C [-300 °F to 500 °F]. Operate point stability is
maintained over the specified temperature range.
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Potential Applications
MILITARY AIRCRAFT AND HELICOPTERS
• Detects landing gear bay doors in closed and locked position
• Senses engine fuel valve position
• Identifies when external hatches and doors are in closed and/or locked position
COMMERCIAL AIRCRAFT AND HELICOPTERS
•
•
•
•
Detects landing gear bay doors in closed and locked position
Senses engine fuel valve position
Identifies when external hatches and doors are in closed and/or locked position
Miscellaneous applications inside commercial aircraft cabin, including waste
management valve position, refreshment (liquids and food) stowed and locked
position, HVAC, and oxygen valve position
AVIATION GROUND SUPPORT EQUIPMENT
• Monitor position of valves, doors or panels, for open, closed, or locked position
SPACECRAFT
• Identifies when external hatches and doors are in closed and/or locked position
• Senses engine fuel valve position
• Select sensing applications inside spacecraft cabin
POWER GENERATION, OIL AND GAS
• Internal switch element in pressure switches, temperature switches, and/or flow
switches
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MICRO SWITCH™ Hermetic Sealed Basic Switches
Table 1. Specifications
Characteristic
Description
Housing material
Mechanical endurance
Electrical endurance
Dielectric voltage (initial)
Circuitry
Contact material
Electrical rating
Sealing
Temperature range
Temperature range (optional)
Vibration
Mechanical shock
Approvals (refer to page 7)
Actuators (auxiliary)
Table 2. Electrical Ratings
Rating code
A
sea level @ 28 Vdc; 3 A res. and 1 A ind.
70,000 feet @ 28 Vdc; 3 A res. and 1 A ind.
sea level @ 115 Vac & 400 Hz; 1 A res. and 1 A ind.
sea level @ 28 Vdc; 1 A res. and 0.25 A ind.
70,000 feet @ 28 Vdc; 1 A res. and 0.25 A ind.
sea level @ 28 Vdc; 0.5 A res. and 0.25 A ind.
70,000 feet @ 28 Vdc; 0.5 A res. and 0.25 A ind.
sea level @ 28 Vdc; 4 A res., 2 A ind. and 1 A lamp
70,000 feet @ 28 Vdc; 4 A res., 2 A ind. and 1 A lamp
sea level @ 115 Vac & 400 Hz; 2 A res., 2 A ind. and 0.5 A lamp
sea level @ 28 Vdc; 4 res. and 2 A ind.
sea level @ 115 Vac and 400 Hz; 2.5 A res. and 2.5 A ind.
hermetic sealed miniature snap-action switch
300 series stainless steel
25,000 operations min.
25,000 operations min.
1000 Vrms for 1 minute
SPDT
silver, gold, gold bifurcated
up to 4 A at 28 Vdc (ref. electrical rating table)
symbol 5, hermetic sealed to MIL-PRF-8805
-65 °C to 121 °C [-85 °F to 250 °F] (see catalog listing table)
-184 °C to 260 °C [-300 °F to 500 °F] (see catalog listing table)
symbol 2 (15 g), 10 to 2000 Hz
shock type M (100 G, saw tooth)
MIL-PRF-8805, UL 508 (File E66520)
straight leaf, roller leaf, straight lever, roller lever
B
C
D
E
Table 3. UL 508 Electrical Ratings
Rating code
F
G
H
J
28 Vdc, 0.5 A res.; -65 °C to 125 °C [-85 °F to 257 °F]
28 Vdc, 3 A res.; -65 °C to 125 °C [-85 °F to 257 °F]
28 Vdc, 0.5 A res.; -65 °C to 260 °C [-85 °F to 500 °F]
28 Vdc, 4 A res.; -65 °C to 260 °C [-85 °F to 500 °F]
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