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This case study highlights an incident where a customer experienced suboptimal performance from their newly installed electric vehicle (EV) charger. Instead of delivering the expected 22kW charging power, the charger was only operating at 3.7kW and underscores the importance of proper wiring in EV charger installations, not just for performance but also for safety.  Discover how we identify the underlying wiring problem, provide a cost-effective solution, and safeguarded our customer’s home while maximizing their charging experience. 

Background: EV Charger charges too slow

A routine call from a distressed customer set the stage for this remarkable case study. The customer had encountered a frustrating problem with a recently installed charger – it charges at 3.7kW instead of 22kW. Previous quotes from other installers had painted a grim picture, suggesting an expensive new installation. Our team, however, decided to approach the issue differently.

Initial Assessment by RExharge:

Understanding the customer’s concern was the first step. The RExharge team promptly arranged a site visit to closely inspect the existing installation. During the visit, we examined the charger, its components, and the overall electrical setup. This meticulous examination led us to a crucial realization – the issue was not with the charger itself but with the wiring and cabling supporting it. 

Safety Hazard of Improper Wiring

Beyond the inconvenience of slower charging, undersized cabling poses a serious safety risk. The undersized wiring was not only limiting the charger’s performance but also creating a significant fire hazard. Electrical systems are designed with safety margins, and when these are exceeded due to improper wiring, the risk of overheating, short circuits, and fires increases dramatically.

According to Energy Commission’s Guideline On Electric Vehicle Charging System ( EVCS ) 5.4.1 :

a) Electric cable for the final circuit shall be protected by means of metal sheath or armor or installed in steel/plastic/PVC conduits. Cable sizing shall be designed according to its current carrying capacity. 

b) The copper conductor size of electric cable for each final circuit shall be selected based on the design current of the EVCS and considering the constraint of voltage drops in the circuit in accordance to its current carrying capacity. A larger size electric cable may be used to facilitate future upgrade.

c) Cables used in final circuits shall be of continuous length and shall contain no joint. 

d) Sample of circuit is illustrated in Figure 8 &9 :

RExharge-Suruhanhaya Tenaga DC Charging System
RExharge-Suruhanjaya Tenaga AC Charging System

During our site visit, we identified that the existing 2.5mm² wiring was operating well below its safe capacity, which could have led to dangerous consequences. By right, a 10mm² wire should have been used. Addressing this issue was not just about improving charging performance; it was about ensuring the safety of the customer’s property and family.

How RExharge’s wiring technicians ensures client’s safety:

Rather than opting for a costly and extensive reinstallation, our team of experienced wiring technicians proposed a more practical solution. Upgrading the existing wiring and cabling (from 2.5mmsq to 10mmsq), we concluded, would rectify the issue and render the charger fully functional.  This simple yet effective wiring upgrade allowed the charger to operate at its full 22kW capacity, restoring optimal performance and eliminating the fire hazard.This solution not only saved the customer significant expenses (save up 80% of their cost) but also showcased our commitment to practical, efficient, and cost-effective resolutions.

Conclusion:

If you’re experiencing issues with your home charger, it’s essential to consider the role that wiring plays in its performance. Inadequate wiring not only reduces charging efficiency but also poses serious safety risks. Choosing a qualified wiring expert can dramatically enhance your Wallbox charging experience while ensuring the safety and efficiency of your home.

For professional advice and cost-effective solutions to your home charging problems, contact RExharge today.  Our team is here to help you ensure that your charging setup is both safe in accordance to Suruhanjaya Tenaga ’s Standard.

RExharge-Schneider Circuit Breaker