Description
Pinpointing blown string fuses in seconds without multimeters.
Mersen CUS101HEL is an industrial 1,000 V DC / 32 A finger-safe modular solar fuse holder featuring an integrated optical blown-fuse LED indicator, engineered to house 10 × 38 mm gPV solar string fuses in commercial combiner boxes with rapid visual troubleshooting.
Integrated Blown-Fuse LED Indicator
Instantly illuminates when a fuse trips, pinpointing faulty solar strings across large combiner boxes in seconds without multimeter probing.
IP20 Finger-Safe Design
Eliminates accidental shock contact with live 1,000 V DC terminals during routine fuse inspection and cartridge replacement.
1,000 V DC / 32 A Heavy Industrial Rating
Specifically engineered to withstand the demanding thermal and direct-current stresses of high-power solar arrays.
Standard 35 mm DIN-Rail Snap Mounting
Compact 1-pole modular design fits seamlessly into standard industrial DC combiner enclosures.
More product details
In a commercial combiner box with 20 string fuses, finding a single blown fuse normally requires disconnecting and probing every holder individually with a multimeter. The CUS101HEL includes an integrated LED circuit across the fuse clips.
- Optical LED illuminates brightly the moment the internal 10 × 38 mm fuse link melts.
- Draws microscopic leakage current (< 1 mA) only when the fuse is open, posing zero risk.
- Drastically accelerates O&M field inspections on commercial solar rooftops.
Certified touch protection on live 1,000 V direct-current circuits.
Direct current does not have zero-crossing points, making live terminal contact exceptionally hazardous. Mersen's UltraSafe housing encloses all live metal contacts inside recessed thermoplastic cavities. Fully compliant with IEC 60269-2 and UL 4248-18 for photovoltaic disconnects. Hinged fuse carrier allows safe extraction of 10 × 38 mm fuses without specialized puller tools. Heavy-duty box-clamp terminals accept copper conductors from 1.5 mm² to 10 mm².
Takes 2 x 6 mm² on the clamp
Rigid or flexible. The screwdriver is PZ2.
Fits string protection in a combiner
The holder is the 10x38 mm seat. Catalogue number is CUS101HEL.
Stops side-by-side at a 0.9 factor
One to three poles stay at 1.0. Four or more take 0.9.
Technical data
Finger-safe optical DC protection engineered for solar string combiner boxes and inverter disconnects.
1000 V / 32 A finger-safe DC fuse holder with integrated blown-fuse LED indicator.
Engineered by Mersen for solar combiner boxes and DC distribution panels, the UltraSafe CUS101HEL holds 10 × 38 mm gPV solar fuses up to 1000 V DC and 32 A. Featuring IP20 finger-safe protection and a built-in optical LED blown-fuse indicator, it speeds up electrical troubleshooting and routine string maintenance without opening live high-voltage circuits.
- Max Voltage
- 1,000 V DC
- Current Rating
- 32 A
- Instant Visual
- LED Indicator
- Finger-Safe
- IP20
Fuse holder
- Fuse size
- 10 x 38 mm cylindrical fuse links
- Number of poles
- 1
- Rated insulation voltage (Ui)
- 1000 V
- Conventional free-air thermal current with fuse links (Ith)
- 32 A
- Degree of protection
- IP 20
Power dissipation
- Maximum power dissipation
- 4 W
- Power dissipation of the fuse-holder alone
- 0.4 W
Installation
- Connection
- Rigid or flexible conductor, max. 2 x 6 mm²
- Screwdriver
- PZ2
- Mounting
- DIN rail, MODULOSTAR modular format
- Application
- String protection in PV combiner boxes
Derating
- Ambient temperature factor
- 1.0 up to 40 °C0.92 at 50 °C · 0.83 at 60 °C · 0.73 at 70 °C · 0.62 at 80 °C
- Poles side by side
- Factor 1.0 for 1 to 3 poles; factor 0.9 for 4 or more
Environment and logistics
- Operating temperature
- From -40 °C
- Storage temperature
- From -50 °C
- Catalogue number
- CUS101HEL
- Manufacturer reference
- K1062724
- Packing quantity
- 12 pieces
Project fit
Where this model fits.
Scenarios that show which projects the Mersen CUS101HEL (1-pole DC fuse holder, 10x38 mm, 1000 V) belongs in, what to verify before quoting, and when another model is the better pick.
DC String Combiner Boxes & Commercial Inverter Inputs (up to 1000 V DC)
Residential and commercial solar installations requiring string overcurrent protection before entering inverters.
Pairs with Mersen HP10M series 10 × 38 mm gPV fuses (such as HP10M20) to provide complete overcurrent protection with LED status.
- Confirm this model against the adjacent rating in the same family
Documents
Mersen CUS101HEL PV modular fuse-holder datasheet (EN) DS-PV-Modular-fuse-holder-CUS101HEL-ENProduct questions
Does the LED indicator work if there is no solar generation (e.g. at night)?
No. The LED requires a voltage differential across the blown fuse to illuminate. The LED indicator is powered by the voltage drop across the blown fuse terminals. When solar strings are generating voltage during daylight, the LED lights up brightly; at night when string voltage is zero, the LED remains unlit.