Backup Power for Glass Studios: Keeping the Concentrator and Kiln Alive in an Outage

Short answer: If your oxygen comes from a wall outlet, a power outage kills your flame within seconds and strands whatever is in your kiln mid-anneal. The honest math for a small home studio is roughly 2.3 kW of running load: a 10 LPM class oxygen concentrator draws somewhere in the ~0.3 to 0.7 kW range (dealer listings disagree, so check your unit’s spec sheet), and a small 120 V annealing kiln like the Paragon SC-2 is rated 1,680 W. That means a small 2 kW generator or budget battery station is not enough to run both at once. The cheapest insurance of all costs nothing: a written finish-in-progress plan for getting the flame off safely and your work into the kiln before the lights go out for good.

This article assumes you already know your oxygen setup; if you’re still deciding between a concentrator and tanks, start with oxygen concentrator vs tanks for lampworking, because tank users can mostly skip the flame half of this problem.

What actually dies the moment the power blinks

Three things in a torch studio are on the grid, and they fail in different ways:

• The oxygen concentrator stops instantly. A concentrator has no meaningful reserve; when the compressor stops, oxygen delivery collapses and your flame goes fuel-rich or dies within seconds. You are suddenly holding hot glass with no working flame. Tank users are immune to this specific failure, which is one of the quiet arguments for keeping even a small backup cylinder around.
• The kiln controller loses its program mid-anneal. A digital kiln that was holding a soak or ramping down is now cooling at whatever rate your kiln’s insulation allows, with no control. What happens next depends on where the glass was in its schedule, covered below.
• Ventilation stops. Your exhaust fan is also on the wall. If the flame is still burning on tank oxygen when the fan dies, you are now torching in a room with no active exhaust, which is its own reason to shut down promptly.

A blip is not an outage

It helps to plan for two different events:

A flicker or a few-second blip. The flame stumbles, the concentrator restarts, and the real question is your kiln controller. Some controllers resume their program after a brief interruption, some restart the segment, and some fault out and sit idle. This behavior varies by brand and model and is exactly the kind of thing to test on purpose during an empty firing. Our kiln controller programming guide covers how programs and segments work; your controller’s manual is the authority on its power-loss behavior, so read that section before you need it.

A real outage measured in hours. Now you are making triage decisions: end the torch session, get in-progress work into the kiln if it is still hot enough, and decide whether backup power is going to carry the kiln through its schedule or whether you accept an uncontrolled cool and plan to re-anneal later.

The watts math, done honestly

Here is where a lot of backup-power advice gets hand-wavy, so let’s use real nameplate numbers and be clear about what is verified and what is not.

The kiln. The Paragon SC-2, a common small 120 V jewelry and annealing kiln, is rated 1,680 watts at 120 volts, 14 amps on the manufacturer’s product page. That is the nameplate figure. In practice a kiln cycles its elements on and off to hold temperature, so the average draw during a long soak is well below nameplate, but your backup power still has to supply the full 1,680 W whenever the elements are on. Larger 240 V studio kilns draw considerably more; check the data plate on yours. For choosing a kiln in the first place, see the lampworking kiln guide.

The concentrator. Published power figures for 10 LPM class concentrators are messy. For the widely used DeVilbiss/Drive 1025 (10 LPM), reseller listings quote figures ranging from about 310 W (claimed for one variant, and possibly a turndown-mode or marketing number) to 639 W average and 670 W on 240 V models. We could not confirm any of these against the manufacturer’s own spec sheet, so treat “roughly 0.6 kW per 10 LPM unit” as a planning number and verify the label on your machine before buying backup hardware.

The total. Concentrator (~0.6 kW class) plus small kiln (1.68 kW nameplate) is roughly 2.3 kW of running load, before you add the ventilation fan, lights, or a second concentrator. On top of that, the concentrator’s compressor motor draws a surge each time it starts. We were not able to verify a specific surge multiplier for these units, but motor start surges are real, and they are why backup power gets sized above running watts, not at them.

Sizing a generator for a torch studio

Generators carry two ratings: running (continuous) watts and starting (surge) watts. Size against your running total with the surge rating comfortably above it. From the math above:

• A 2 kW class inverter generator cannot run a ~0.6 kW concentrator and a 1.68 kW kiln at the same time. It is a concentrator-and-lights machine, useful for finishing a piece but not for carrying an anneal.
• To run concentrator plus small kiln together, you need a generator whose continuous rating clears ~2.3 kW with headroom for compressor starts and whatever else is on the circuit. Undersizing is not just inconvenient: a generator that browns out under load feeds low voltage to a compressor motor, which is hard on the concentrator.
• If your torch needs two concentrators, add another ~0.6 kW class load per unit to the total.

Be conservative, and check your specific equipment’s requirements against the generator maker’s guidance. The manufacturer manuals for your kiln, concentrator, and generator take precedence over any general figure in this article.

Battery-inverter stations: runtime arithmetic

Battery power stations (a battery plus inverter in a box) are quiet, indoor-safe, and instant-on, which makes them attractive for the blip problem. The catch is runtime, and the arithmetic is simple division:

• A 1 kWh battery running a ~600 W concentrator lasts under 2 hours, less after inverter losses.
• The same 1 kWh feeding a kiln at its full 1,680 W nameplate is gone in about 35 minutes. During a soak the elements cycle, so real runtime is better than that worst case, but a small battery is still not an hours-long anneal solution for most kilns.

Where batteries genuinely shine is bridging: riding through flickers without the controller ever noticing, and buying you 30 to 60 minutes to shut the torch down gracefully or to let a nearly finished piece get safely into the kiln. Check that any station you buy can actually deliver your kiln’s or concentrator’s wattage continuously, and confirm compatibility with the equipment manufacturer; we did not verify specific brands or models for this article.

Generator safety is non-negotiable

The safety rules here are absolute, and your generator manual and local electrical code override anything on this page:

• Outdoors only. Always. Never run a generator inside the studio, the house, a garage, or any enclosed or partially enclosed space, even with doors open. Generator exhaust contains carbon monoxide. Follow the manufacturer’s placement and clearance instructions, keep exhaust pointed away from openings, and treat your CO detector as mandatory equipment.
• Never backfeed. Plugging a generator into a wall outlet to energize house wiring is dangerous to you and to utility workers. If you want the generator to feed studio circuits, have an electrician install a proper transfer switch or interlock to code. Otherwise, run appliances on appropriately rated extension cords directly from the generator.
• Fuel discipline. Store generator fuel per the manufacturer’s instructions, away from the studio’s oxygen and torch fuel, and shut the generator down to refuel.

The cheap insurance: a finish-in-progress plan

Hardware is optional; a plan is not. Write yours down and tape it near the bench:

1. Kill the flame safely. The moment the concentrator dies, follow your normal shutdown order and close the fuel at the source. Do not stand there tuning a dying flame.
2. Get the work into the kiln if the kiln is at temperature, or park small work in a fiber blanket as a distant second best.
3. Know your controller’s power-loss behavior in advance, from the manual and from a deliberate test, so you know whether the program resumes on its own when power returns.
4. Decide the re-anneal question ahead of time. Common studio practice treats glass that had already cooled below the strain point as safe, while work that lost its soak mid-schedule may survive the uncontrolled cool but should be re-annealed before you trust it. We could not verify this against a manufacturer technote for this article, so when in doubt, run the piece through a full schedule again; see annealing schedules for glass for how to set one up.

Which torches this actually matters for

Backup power for the flame side only matters if your oxygen comes from a wall outlet. Using the concentrator specs from our catalog, here is roughly what the electrical load looks like per torch, assuming ~0.6 kW class per 10 LPM concentrator (verify your unit’s label):

Tank-fed production torches sit outside this problem entirely: their oxygen keeps flowing in an outage, and the backup-power question reduces to the kiln and the ventilation fan.

Key takeaways

• An outage kills a concentrator-fed flame in seconds and strands the kiln mid-anneal; plan for both.
• Honest running load for a small studio: ~0.6 kW class for a 10 LPM concentrator (published figures range ~310 to 670 W, so check your spec sheet) plus 1,680 W nameplate for a Paragon SC-2 class kiln, roughly 2.3 kW together, before motor start surges.
• A 2 kW generator or small battery is too small for concentrator plus kiln at once; size above running watts with surge headroom, or use a battery station as a bridge, not an anneal-length supply.
• Generators run outdoors only, never backfed; use a transfer switch or interlock installed to code, and let the manufacturer manuals override anything here.
• The best value in the whole topic is a written finish-in-progress plan: flame off safely, work into the kiln, controller behavior known in advance, re-anneal when in doubt.

Sources

• Paragon Industries, “SC-2 jewelry kiln” (120 V, 1,680 W, 14 A specifications): https://paragonkilns.com/products/sc2-jewelry-kiln

Editor’s note: concentrator power-draw figures in circulation vary widely (roughly 310 to 670 W for 10 LPM class units, depending on model, variant, and voltage) and were not confirmed against a manufacturer spec sheet for this article. Kiln wattages, controller power-loss behavior, and generator ratings vary by model. Always verify against the data plate and manual for your specific equipment, and follow your generator manufacturer’s safety instructions and local electrical code.