Every branch in a DC power distribution unit depends on a contactor that does what it is told. Albright HV500 is a sealed single-pole contactor for 12 to 1000 V DC and thermal currents up to 500 A, so one part can serve many branches of your PDU.
Run it yourself
Choose a coil and an auxiliary switch, then power the coil up and down. The contactor, the meters and the cut-away react to every move. Switch on 'Main contact sticks' and watch what the mirror contact does about it.
Coil power
Load power (example values you set)
AUX wires, step by step:
Coil options and auxiliary switch, explained straight
PWM coil economiser
Closing a contactor takes a hard push. Keeping it closed takes almost nothing. The PWM economiser board is fitted at the Albright factory and handles that difference for you.
- Pull-in. The coil receives 27 W and the contacts are shut in less than 20 ms.
- Holding. The board chops the coil supply at high speed. The coil then averages 3 W, roughly one ninth of the pull-in figure.
- Release. Cut the supply and the contacts are open in less than 5 ms. With the PWM board on board, back EMF is 0 V and the coil is suppressed.
What you gain: a cooler coil and a lighter load on your supply. Coil voltages run from 12 to 96 V DC, and swapping the red and black leads by mistake does no harm because the board is reverse-polarity protected.
Watch out: give it clean, smooth DC. A ramping supply voltage is not compatible with the PWM board. The hermetic seal covers the PWM circuit as well.
Magnetic latching
A permanent magnet in the coil assembly keeps the contacts where you left them. You only use the coil when you want to change state.
- Close. Give it a pulse of roughly 500 ms, plus to the red lead and minus to the black lead. The coil takes 12 W for the duration.
- Hold. You do nothing. It stays closed at zero watts.
- Open. Reverse the polarity for 200 to 500 ms: minus to red, plus to black.
What you gain: no coil power at all while nothing moves. Ideal for packs that stay connected for long stretches, or where coil heat is a problem.
Watch out: a latching contactor is not failsafe. If control power fails it stays put and does not open on its own, so plan your system around that.
Intermittent duty
The intermittent (INT) coil is made for switching on load, or for builders who run their own PWM circuit.
- Run your own PWM at 10 kHz or above. Albright's best results come at 15 to 20 kHz.
- Short-duty jobs such as pump control: ask Albright Technical.
Unsure which coil fits? Describe your application and we get Albright's view.
Mirror contact: proof, not a guess
The risk: turning the coil off is only an order. It does not show that the main contacts really opened. If they stick together after hard switching, the pack stays connected while your system believes it is off.
The fix: order the auxiliary switch as normally open (white wires), normally closed (blue wires) or mirror, NC (orange wires). The mirror contact is tied to the main contacts and is closed only while they are open. Your controller therefore gets evidence that the load is cut off. Test it in the demo above: pick Mirror, switch on 'Main contact sticks (fault)' and cycle the coil.
Albright describes the mirror contact as a failsafe status signal for the main contacts, in normal running and in a fault, and refers to EN 60947-4-1 Annex F and EN 60947-5-1 Annex L. The demo illustrates the principle. The normally open and normally closed options are drawn here as following the contactor operation; ask us how they behave in your design. Auxiliary switch rating: 1 A at 24 V DC resistive, minimum 100 mA at 12 V.
PDU designers: check these first
Size the conductor
250 A continuous on 50 mm² (1-1/0 AWG) cable, up to 500 A on 190 mm² (350 MCM) busbars. Thermal ratings follow the conductor you use.
Pre-charge for capacitors
Capacitors in the unit? Albright requires pre-charging. Decide it before you decide the contactor.
Made for switching under load
Silver alloy tips are available for frequent load switching, and Albright publishes make and break limits. Test your numbers against them.
Mount and connect your way
Terminals M6 or M8 female, M8 or M10 male. Bracket in six angles. Optional terminal guard over the studs.
Specifications at a glance
| Rated contact voltage | 12 V – 1000 V DC |
|---|---|
| Current | 250 A continuous with 50 mm² (1-1/0 AWG) cables; up to 500 A with 190 mm² (350 MCM) busbars |
| Coil voltages | 12, 24, 36, 48, 60, 72, 84, 96 V DC |
| Operating temperature | −45 °C to +85 °C (higher possible with current derating) |
| Shock and vibration | 20 G peak shock; 80–2000 Hz sinusoidal vibration, 20 G peak |
| Mechanical life | Main contacts over 10⁶ cycles |
| Insulation and dielectric | Over 200 MΩ; 4000 V DC withstand, leakage under 1 mA |
| Weight | Switch 400 g, bracket 20 g |
| Mounting | Rotatable bracket with six angles |
| Recognition | UL Recognised (product status is shown on Albright's website) |
Typical jobs
Albright puts power distribution units on its list of typical applications for the HV series. Tell us how your PDU is built and we pick terminals, coil and auxiliary switch with you.
Engineering notes from Albright
Capacitive loads
Capacitors in your circuit? Then you need pre-charging.
Latching is not failsafe
With a magnetic latching coil the contacts stay in their last state when power is gone. Design for it.
Smooth DC for PWM
The PWM board expects steady DC. It does not work from a ramped supply voltage.
Verify in your application
Treat the data as a guide. Some derating may apply, so Albright advises proving the performance in your own application.
Send the PDU requirements, get the right HV500
Give us voltage, current per branch, load type and switching rate and we propose the configuration. Many units? Ask for a quote. One to test? Order it right now.
Quick answers
Does it count as a safety device?
No. It is a contactor for switching DC loads. Safety functions and the safety design remain with the equipment designer.
Can it open and close with load on?
Yes, inside Albright's make and break current limits. Silver alloy tips are an option when you switch under load often. Check the figures for your voltage and current.
Which coil is right for me?
PWM economiser: low holding power. Magnetic latching: zero holding power. Intermittent: you bring the PWM. Tell us the application and we make the call with you.
Is it serviceable?
No. The hermetic seal means HV contactors cannot be serviced.
Which terminals are available?
M6 and M8 female, M8 male (standard) and M10 male, as listed by Albright. Tell us your cable or busbar and we choose the best fit.
Albright International Ltd designs and manufactures the HV500. OEM NORDIC, a business name of MK-Controls Oy and an Albright distributor, supplies it. Figures come from the Albright HV500 catalogue and can change without notice. The animation is a simplified illustration.