Question 1

What is the HX series and what applications is it built for?

Accepted Answer

The GIGAVAC HX series is a hermetically sealed high-voltage DC contactor family that combines 1500 Vdc switching and up to 1000 A continuous current in a remarkably compact package — a class-leading performance level few competitors match. Thanks to the patented EPIC® ceramic insulation it switches across 12 to 1500 Vdc, both at low and high voltages. UL508 certified for hot switching at parameters as high as 1000 V, the HX is the smallest such contactor in the world. It is preferred for 1500 V solar inverters, battery boxes, wind power systems, electric buses and trucks.

Question 2

What is EPIC® insulation technology?

Accepted Answer

EPIC stands for "Extended Performance Impervious Ceramic" — GIGAVAC's patented ceramic insulation technology, in production since 2006. It allows the HX series to switch up to 1500 Vdc inside a far more compact body than conventional designs. The hermetic build fully isolates the device from environmental effects, while EPIC® safely quenches the high-voltage arc. The same EPIC® seal lets these high-voltage contactors exceed IP67 and IP69 — they operate even submerged. The same technology is used in the GX and MX families.

Question 3

What are the current and voltage ranges of the HX series?

Accepted Answer

Continuous contact current spans 200 A (HXNC241) to 1000 A (HX460), with 300 A (HX22), 350 A (HX21, HX200) and 400 A (HX241) in between. Every model is rated for 1500 Vdc switching. The 12-to-1500 Vdc usable range makes the HX ideal for modern high-voltage battery packs at 800 V, 1000 V and 1500 V.

Question 4

Why is the HX called the world's smallest contactor of its class?

Accepted Answer

Conventional 1500 V DC contactors are big and heavy. Thanks to EPIC® insulation, the HX series delivers the same switching capacity in a far more compact body. HX21 and HX241 weigh just 0.38-0.44 kg — under half a kilogram. The result: minimum panel footprint, compact integration in battery boxes and ESS modules, and a real weight advantage in EV buses and trucks.

Question 5

What is hot switching and why does it matter?

Accepted Answer

Hot switching is the ability to open and close the contactor under live load. Most DC contactors are rated only for cold switching (after current is cleared) — opening under load forms an arc that damages the contacts. The HX is UL508-certified for hot switching at parameters as high as 1000 V, which is critical for emergency stop, protection circuits and applications with dynamic load changes.

Question 6

What is the mechanical life of the HX series?

Accepted Answer

Every HX model is rated for 1,000,000 mechanical cycles. Even in high-frequency switching this represents many years of service life — at 100 cycles per day, theoretical life exceeds 27 years. It delivers long-term reliability in EV buses, solar inverters and always-on ESS systems.

Question 7

In which environmental conditions does the HX operate?

Accepted Answer

The HX operates from -55 °C to 85 °C. With IP67 and IP69K protection it is fully sealed against water and dust — IP69K means it withstands high-pressure hot water washdown. This makes the HX safe for outdoor solar inverters, EV truck and bus underbody systems, wind turbine nacelles and humid industrial environments.

Question 8

Which variants exist in the HX series?

Accepted Answer

The HX series consists of 6 main models:
• HX21 — 350 A, the most popular model
• HX22 — 300 A
• HX200 — 350 A
• HX241 — 400 A
• HX460 — 1000 A (highest-current model)
• HXNC241 — 200 A normally-closed (NC) variant

Each main model has coil-voltage sub-variants: HX21CAB (24 V), HX241BAB (12 V), HX241CAB (24 V), HX460CAA (24 V), and so on. All models switch up to 1500 Vdc.

Question 9

How are HX contactors used in electric vehicles?

Accepted Answer

The HX is the flagship high-voltage contactor family for EVs that use high-voltage battery systems — electric buses, trucks and other heavy electric vehicles. Typical EV uses include the main battery contactor, DC fast-charge inlet contactor, pre-charge circuit, auxiliary-load (HVAC, compressor) isolation, and emergency disconnect. Its 1500 V capability easily covers modern 800 V and 1000 V architectures where traditional sub-800 V contactors fall short. For megawatt charging (MCS) and heavy electric vehicle projects, the HX is the default choice.

Question 10

How are HX contactors used in solar and wind applications?

Accepted Answer

The HX is purpose-built for renewable infrastructure and is the standard contactor choice for 1500 Vdc utility-scale solar. It is used as the DC input contactor in string inverters, the main DC disconnect in central inverters, the combination/protection contactor in solar combiner boxes, and the battery connect/isolation contactor in hybrid ESS. Over 90 % of modern utility-scale solar runs on 1500 Vdc, where the HX is one of the few valid solutions. In wind turbines it is preferred for nacelle-internal DC links and crowbar protection. IP67 & IP69K protection makes it ideal for outdoor and humid environments.

Question 11

What is the key difference between the HX and GX series?

Accepted Answer

HX and GX make up GIGAVAC's high-voltage families and share the same patented EPIC® ceramic insulation, but they target different segments:

• GX series: switching up to 800 Vdc, 26 models, ideal for EV main contactors and general industrial use.
• HX series: switching up to 1500 Vdc, up to 1000 A continuous, class-leading performance in a compact body, UL508 hot switching, 1,000,000-cycle mechanical life.

Under 800 V choose GX; above 800 V — and especially at 1500 V — choose HX. For modern utility-scale solar (1500 V), electric bus/truck (800 V+) and megawatt charging, HX is the standard choice.

Question 12

When is the HXNC241 normally-closed contactor preferred?

Accepted Answer

The HXNC241 is the normally-closed (NC) variant of the HX series. Where standard NO models close on coil energise, the HXNC241 opens on coil energise — and the contact auto-closes when the coil is de-energised. It is preferred in safety-critical applications: emergency stop (E-stop) systems, fail-safe circuits, passive battery connection systems and crowbar protection. It offers 200 A continuous current and 1500 Vdc switching.

Question 13

Which standards does the HX series comply with?

Accepted Answer

The HX complies with:
• UL508 (Industrial Control Equipment) — hot-switching certification
• IP67 (dust-tight + 1 m submersion)
• IP69K (high-pressure hot-water washdown)
• RoHS
• CE Mark of Conformity

For EV and solar certification specifics, a Sensata application review is recommended.

Question 14

How is an HX contactor mounted?

Accepted Answer

Thanks to their compact build HX contactors can be mounted in any orientation. Their small size (~0.38-0.44 kg) means a minimum panel footprint and reduced vibration load. Stainless-steel mounting inserts ensure years of corrosion-free service in humid and vibrating applications — suitable for EV underbody chassis mounting, in-battery-box mounting and solar inverter panel mounting alike.

About the HX Series series

01What is the HX series and what applications is it built for?

02What is EPIC® insulation technology?

03What are the current and voltage ranges of the HX series?

04Why is the HX called the world's smallest contactor of its class?

05What is hot switching and why does it matter?

06What is the mechanical life of the HX series?

07In which environmental conditions does the HX operate?

08Which variants exist in the HX series?

09How are HX contactors used in electric vehicles?

10How are HX contactors used in solar and wind applications?

11What is the key difference between the HX and GX series?

12When is the HXNC241 normally-closed contactor preferred?

13Which standards does the HX series comply with?

14How is an HX contactor mounted?