You may also like
Mersen GSC1/2 Time-Delay Glass Fuse, 250V 0.5A, 100-Pack
The Mersen GSC1/2 is a time-delay glass fuse rated 250V at 0.5A in a compact 5x20mm glass body, sold in a convenient 100-pack for maintenance stock or high-volume assembly. Its time-delay characteristic allows it to ride through brief inrush current spikes while still opening reliably on sustained overcurrent, making it a dependable choice for protecting sensitive electronic and control circuits. The GSC series carries UL Listed and CSA Certified recognition across its ampere range, giving specifiers a code-aware option for OEM and replacement fuse applications.
Key Features
- Compact Dimensions: 5mm x 20mm glass fuse body fits standard fuse holders and clips sized for this common form factor.
- Glass / Ceramic Body: Clear glass construction allows visual inspection of the fuse element for quick troubleshooting.
- Time-Delay Response: Time-delay (slow-blow) characteristic tolerates momentary inrush current without nuisance opening, while still clearing sustained faults.
- 0.5A / 250V Rating: Rated for 0.5A at 250V, suited to low-current circuit protection in electronic and control equipment.
- Ferrule Termination: Ferrule-style connection terminals for secure seating in compatible fuse clips and holders.
- Bulk 100-Pack: Packaged 100 to a box for stocking programs, production lines, and field service inventory.
Certifications & Compliance
- 1/10A through 3A, 250VAC, UL Listed and CSA Certified
- 4A through 8A, 125VAC, UL Listed and CSA Certified
- 10A, 125VAC, UL and CSA Recognized
Technical Specifications
- Ampere Rating: 0.5 A
- Connection Terminal Type: Ferrule
- Country Of Origin: CN
- Mounting Method: Clip
- Product Diameter: 0.2 in
- Rated Voltage Ac Ul: 250 V
- Speed Characteristic: Time Delay
Typical Applications
- Electronic Equipment and Circuit Board Protection
- Control Panels and Industrial Control Circuits
- OEM Equipment Fuse Replacement
- Instrumentation and Low-Current Device Protection
- Maintenance and Spare-Parts Stocking
Why Mersen?
Mersen's GSC series glass fuses combine a time-delay response with UL Listed and CSA Certified recognition, giving electrical professionals a documented, code-aware option for circuit protection. The glass body construction supports quick visual verification of fuse condition, reducing troubleshooting time in the field or on the bench. With ferrule terminations and a standard 5x20mm form factor, the GSC1/2 drops into existing fuse holders for reliable, repeatable protection across electronic and control applications.
Manufacturer Resources
Spec Sheet
Product Specs
- Product Group:
- Wiring Devices
- Body Insulating Material:
- Glass / Ceramic
- Product Diameter:
- 0.2 in
- Product Line:
- GSC - Time-Delay
- Speed Characteristic:
- Time Delay
- Connection Terminal Type:
- Ferrule
- Department:
- Electrical
- Country Of Origin:
- CN
- Product Type:
- Fuse
Mersen GSC5 – Frequently Asked Questions
1) What amperage ratings does the Mersen GSC time-delay fuse come in?
Six orderable ratings: 0.25A (GSC1/4), 0.5A (GSC1/2), 4A (GSC4), 5A (GSC5), 6A (GSC6) and 8A (GSC8). Note the voltage rating is not the same across the range. Per the GSC data, 1/10A through 3A are rated 250VAC, while 4A through 8A are rated 125VAC. So if you are protecting a 230V control circuit, only the 0.25A and 0.5A parts in that group carry the 250V rating.
2) Do I need a time-delay fuse or a fast-acting one for a control panel with a transformer?
A transformer, motor starter coil, or switch-mode power supply draws a heavy inrush spike at energization, and a fast-acting fuse will often open on that spike alone. The GSC series is time-delay (slow-blow), so it rides through that momentary surge and still opens on a sustained overcurrent. Use fast-acting where the load is resistive or where you are protecting semiconductors that need to clear quickly. Littelfuse's BLF series is a fast-acting midget fuse rated 250V if that is the direction you need.
3) What is the difference between a Mersen GSC5 and a Littelfuse AGA5 glass fuse?
Both are 5A glass-body fuses, but they are different form factors and response types. The Mersen GSC5 is a 5A member of the GSC time-delay line in a 5x20mm glass body with ferrule terminations, so it rides through inrush on control and electronic circuits. The Littelfuse AGA5 is a 5A glass fuse from the AGA series. If the holder is clipped for the 5x20mm metric body and the circuit has a transformer, motor, or power supply inrush behind it, the GSC5 is the time-delay choice; the AGA5 belongs in holders prepped for the AGA series body.
4) I need a 0.5A fuse for a power meter - is the Mersen GSC1/2 the same as the Square D PowerLogic fuse pack?
They are not interchangeable. The Square D PowerLogic Energy Meter Fuse Pack is a set of three fuses rated 0.5A at 600V, matched to meter voltage-input circuits fed from a 600V system. The Mersen GSC1/2 is also 0.5A but rated 250V AC in a 5x20mm glass body with a time-delay characteristic. The voltage rating is the deciding spec: a 250V fuse does not belong on a 600V metering input. For 5x20mm holders on 250V control and electronic circuits, the GSC1/2 is the time-delay part, and it is sold 100 to a box for stocking.
5) Can I use a Littelfuse BLF midget fuse in place of a Mersen GSC time-delay fuse?
No. The Littelfuse BLF is a midget fast-acting fuse rated 250V in a laminated tube body, while the Mersen GSC series is a time-delay glass fuse in a 5x20mm body with ferrule ends. Two things stop the swap: the midget body will not seat in clips sized for the 5x20mm form factor, and fast-acting response will open on the inrush a time-delay GSC is chosen to ride through. Use the BLF where the drawing calls for a midget fast-acting fuse and the holder is sized for it; use the GSC for slow-blow protection in 5x20mm clips.
6) I need a 5 amp glass fuse but mine is fast-acting, not slow-blow. What else is there?
Do not substitute a time-delay GSC5 into a circuit specified fast-acting, and do not go the other way either. The two clear at different speeds and the fuse coordination on that circuit was chosen deliberately. For a fast-acting 5A glass fuse, Littelfuse's AGA5 in the AGA series is the direct type match. For panel-mounted midget protection at 250V there is the Littelfuse BLF fast-acting series.
7) Will a GSC fuse mount on a circuit board or does it need a holder?
It needs a holder. The GSC uses ferrule end caps and a clip mounting method, so it drops into spring clips on a board, into a panel-mount fuse carrier, or into an in-line holder sized for 5x20mm. There are no leads to solder. If your board is prepped for an axial-lead or pigtail fuse, this is not the part.
8) Both the Mersen GSC and the Littelfuse CCMR are time-delay fuses - when would I use one over the other?
They protect very different circuits. The Littelfuse CCMR040 is a Class CC time-delay fuse rated 40A, a branch-circuit fuse for motor and transformer protection in rejection-style Class CC holders. The Mersen GSC series is a 5x20mm glass time-delay fuse topping out at 8A, intended for electronic equipment, circuit boards, instrumentation and control circuits inside a panel. Size the CCMR to a feeder or motor circuit and the GSC to the low-current secondary or device it feeds.
9) Can I tell if a GSC glass fuse is blown without a meter?
Usually yes. The GSC body is glass, so the element is visible through the tube and a cleanly opened fuse shows a broken or vaporized wire. A hard short can deposit metal on the inside of the glass and darken it, which also reads as blown at a glance. Ceramic-bodied fuses give you no such indication and have to be checked with a meter.
10) How are Mersen GSC fuses packaged for maintenance stock?
Bulk, 100 to a box. That is the packaging on the GSC time-delay glass fuses, which is what you want for a stocking program, a production line, or a service van where you are burning through a single rating repeatedly. If you only need a handful of one value, a bulk box is more than the job takes.
How fast can I get the Mersen GSC5 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the
continental
U.S.
Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit,
reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Mersen GSC5 come with a warranty?
Absolutely. The Mersen GSC5 is backed by a manufacturer’s warranty.
For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Mersen GSC5?
You can call, text, or email our expert support team for fast answers. We’re here to help with
product
selection,
installation tips, and troubleshooting. Contact Us
Why buy the Mersen GSC5 from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support,
and
rewards on
every order.
Our team is always ready to help you choose the right product for your project.