Wall Charger Repair – Suntron

• Yellow MC120: 120 VAC, 15 A (slow).
• UMC / MC240: 240 VAC, up to 40 A (much faster).
• Suntron HPWC (Gen 1): 208–240 VAC, up to 70 A — high-current turnaround charging for Roadster owners and shops.

We provide component-level repair for the Suntron Roadster wall charger, including diagnostics and rework of the control electronics, plus verification on Roadster-compatible charging test equipment. Flat-rate board repair starts at $895.

• Control/logic board troubleshooting, component replacement, and functional validation.
• Power switching inspection (contactor/relay path), thermal checks, and fault reproduction testing.
• Charge-handshake verification and safety interlock checks before return shipment.

Why the original Roadster 1.5 “Suntron” wall charger won’t reliably charge a 2.X Roadster

Early Tesla Roadster 1.5 cars could be paired with an optional High Power Connector (HPC) wall charger—often referred to in the community as the “Suntron” unit (you’ll still see it described that way on the secondary market).  When Tesla released the next-generation Roadster 2.0/2.5 (“2.X”), owners discovered a common incompatibility: plugging a 2.X Roadster into the early HPC can trigger a “Ground Fault” error and terminate charging.

What actually happens

The symptom is classic nuisance ground-fault behavior:

1. You connect the car and it attempts to begin charging.
2. The wall unit detects leakage current to ground (or interprets what it sees as leakage).
3. It trips into a ground-fault lockout and charging stops.

On Roadster charging equipment, “Ground Fault” is exactly what it sounds like: the EVSE is watching for unintended current paths to earth/ground and will shut down charging when it believes a fault is present.

Root cause: different leakage behavior + tighter early GFI threshold

From community troubleshooting history, the key details are:

• The original Roadster HPC used a lower (more sensitive) GFI threshold, and
• 2.X Roadsters tend to present more leakage-to-ground behavior during charging (often tied to differences in onboard charger / EMI filtering and vehicle-side hardware),
• which makes the early HPC more likely to interpret a 2.X car as a ground-fault condition and trip.

In plain English: nothing “mystical” is wrong with the 2.X car—it simply presents a slightly different electrical signature, and the early HPC’s protection circuitry can be too trigger-happy for it.

Why Tesla moved to ClipperCreek (TS70) for the Roadster wall charger

To solve the compatibility issue (and standardize a robust, production-ready EVSE), Tesla sourced the Roadster high-current wall charger from ClipperCreek, built around the TS70 platform—commonly referenced as Tesla’s Roadster HPWC/HPC successor.