RUSHES TO ELECTRIFY, AS THE OFF-ROAD VEHICLE MARKET STANDARDS

ARE LAGGING BEHIND.

Construction vehicles are being electri ed at a surprisingly rapid pace, as operators recognize not only the cost savings, but the advantages of silent, emission-free operation. However, the high power requirements of these vehicles mean that vehicle designers face unique technical challenges, especially when it comes to circuit protection.

High-voltage DC current is more dangerous and harder to interrupt than the comparatively sedate 48 volts used in smaller vehicles. Unfortunately, thanks to the fast pace of electri cation and the slow pace of standards bodies, electrical safety standards for heavy vehicles are lagging behind the market.

As the industry gets ahead of the standards, the uncertainty is delaying time to market for many companies, and cutting into pro ts (to say nothing of potentially endangering peoples’ safety).

Circuit protection specialist Littelfuse began its history selling products for the Ford Model T, and it makes circuit protection components for every kind of vehicle imaginable. Geo rey Schwartz, Business Development Manager at Littelfuse Commercial Vehicle Products, told Charged some stories to illustrate the chaotic situation that’s delaying the move to EVs.

Littelfuse has seen designs using 32 V fuses for 600 V systems, and companies using industrial fuses because high-voltage automotive-quali ed fuses aren’t available. When engineers specify components that aren’t automotive-rated, they are then forced to spend time in extensive testing to make sure their vehicles don’t catch re.

Suppliers have to guess at what the eventual standards will look like, and try to ensure that their products will meet the standards when they’re nally published.

Q Charged: So, there’s a lack of standards for vehicles that use higher-voltage electrical architectures?

A Geo Schwartz: Yes. All the standards organizations are running behind. I’m on the SAE Truck and Bus Electrical Systems Committee, and I know we are trying to write 48-volt standards now. We are looking at a few higher-voltage standards, but the real standards, they’re probably three to ve years out. It takes so long to write a standard, for everybody in the industry to come together and come to an agreement. e standards committees just don’t move that fast.

We’re seeing a series of electrical architectures, with one group around smaller equipment at 48 volts, and a medium range—200 to 500 volts—in large equipment and medium-duty trucks. en as you get into larger vehicles—