Coils for Solenoid-Operated On/Off and Proportional Valves

E-Coils — Waterproof, Weather-Resistant, IP69K Rated
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Thermal Shock Dunk Test Rated
E-Coils with leadwires, Deutsch DT
and Metri-Pack connectors have
passed what is known in the
construction, agricultural and mobile
equipment markets as the Thermal
Shock Dunk Test. (See below.)
Easy Installation
No O-rings, external sealing, or waterproofing kits required.
IP69K with Integral Connectors
and with New Dual Leadwires

Models with Deutsch DT and Metri-Pack
connectors as well as the new dual leadwire
models are rated for IP69K. DIN and dual
spade connections are rated for IP65.
(See below).

Fully Encapsulated

Coils are fully encapsulated for
zero leak paths when ordered
with integral connector options.
    Field Retrofit-able
In most cases, E-coils can be used to
replace existing coils on HydraForce
valves already in operation.
Shock Resistant
Integral grommet for Deutsch DT
connectors increases durability
under conditions of high random
Rugged Metal Shell
The rugged external metal shell
provides exceptional protection
against physical damage,
ensuring durability under harsh
operating conditions. It is salt
spray rated for 1000 hours per
ASTM B117 specifications.
Note: Some E-Coils, including
those manufactured prior to
Jan.1, 2004, may differ slightly in
construction from this illustration.
See E-Coils PDF brochure,
page 3.400.17
High Temperature Operation
Class N 200°C (392°F) magnetwire and
insulation materials allow high temperature
operation and ensure long life under
demanding conditions. Continuous duty
operation up to 100C and 115% of
nominal voltage.


As of January 2004, HydraForce has made design changes to the industry-leading environmentally-hardened Series E coils. The new design provides longer life under high-temperature conditions, as well as easier and more convenient interchange with our Series D standard-duty coils.

The Story Behind the Ratings
To appreciate the performance of the new Series E coils, it is helpful to have a working knowledge of the testing conducted to assure coil life in the harshest environments. Many OEMs request a coil that is IP67 or IP69 rated. These ratings do not address the issue of the effect of high temperatures on coil life and operation. Therefore they are of limited value in evaluating the suitability of a coil for use in typical mobile equipment applications.

Why temperature matters: When a coil is heated, the air inside the coil expands, creating internal pressure, causing the heated air to attempt to exit the coil. If the coil is then submerged in cold water, the air within the coil cools and contracts, drawing water into the coil through any seams or voids in the coil encapsulant. Eventually the water will find its way into the winding area, causing the coil winding to corrode or short-circuit, resulting in coil failure.

IP ratings are international specifications for electrical equipment which define various levels of protection against failure resulting from contamination by water or other foreign substances. The IP67 rating is based on submerging the coil one meter of water for 30 minutes. The coil is then inspected for evidence of water infiltration. The IP67 specification loosely states that ingress of water in quantities causing harmful effect shall not occur. The exact meaning of the phrase harmful effect is not precisely defined, and is therefore open to some interpretation. In this test, the coil is not subjected to high temperatures, so the effects of thermal stress are not considered.

The IP69 rating, which is currently only part of the DIN version of this specification, first requires that the coil pass the test for IP67 as described above. Beyond that, the coil and its integral electrical connector are subjected to a rigorous high-pressure water spray. The water is mixed with detergent, is held at a temperature of 80C, and is sprayed at the coil from a distance of 100 mm (4 inches) at a pressure of 100 bar (1450 psi). Again, the specification does not precisely define the amount of water ingress that would be considered unacceptable.
HydraForce Ratings
Working with major mobile equipment OEMs, HydraForce has developed even more rigorous tests that are designed to assure that our coils will perform reliably under the harshest real-world application conditions. Both our original and our new Series E coils meet or exceed the requirements of what is known as the Thermal Shock Dunk Test. In this test the coil is thermally soaked for two hours in an ambient temperature of 100C. The coil is then immersed immediately in a 0C saltwater bath for two hours. This procedure is repeated ten times. The coil is then inspected for water ingress. By Hydraforces standards, the coil is considered to have passed this test if there is NO detectable water ingress, as determined by visual inspection and a high pot test. This standard requires a totally sealed coil that is impervious to moisture infiltration, even under widely varying ambient thermal conditions.

The new Series E coils can withstand at least 10 cycles of the Thermal Shock Dunk Test.

In addition to the requirements of the industry-recognized, Thermal Shock Dunk Test, described above, HydraForce further tests these coils for durability against failure due to vibration, as well as against failure due to the application of voltage above the coils standard duty rating while it is simultaneously subjected to continually varying ambient temperatures.

Beyond enhancing the durability of the coils, we have decreased the wattage by approximately 10%. This reduces the power consumption and also allows the operating temperature range to be extended. The new design also improves the ease and convenience of interchanging these coils with HydraForces Series D (standard duty) coils, the original Series E coils, as well as the older W-style waterproof option. The new Series E coils use the same retaining nuts as the Series D coils, simplifying interchangeability, inventory and assembly requirements and procedures.

See page 3.400.17 for detailed information describing the differences between the original Series E coils and the new Series E coils, including part number cross-references for the coils, the retaining nuts, and the spacers used on the dual-solenoid valves.
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