The box that keeps electricians alive — fusible vs. non-fusible, lockout/tagout, NEMA ratings, and the steady used market.
A disconnect switch (safety switch) does one job: visibly and reliably open a circuit so equipment can be serviced dead. Code requires one within sight of nearly every motor, HVAC unit, and major appliance. They are simple, cheap, everywhere — and the used market for fusible disconnects is deeper than most people guess.
Fusible safety switches have steady resale. Send photos →
Fusible disconnects hold fuses — overcurrent protection plus disconnect in one box. Non-fusible is just the switch — used where protection lives upstream. Fusible units cost more new and hold more value used; always state which yours is.
General-duty (240V max, lighter construction) for residential and light commercial; heavy-duty (600V, rugged) for industrial. The heavy-duty line — Square D HU, Eaton DH — is the one the used market wants.
Disconnects come in every enclosure type: NEMA 1 indoors, 3R outdoors, 4X washdown, 7/9 hazardous. The enclosure rating is half the value proposition — see our NEMA guide.
A disconnect’s real job is lockout/tagout (LOTO): the electrician opens the switch, applies a personal padlock, tags it, and only they hold the key. No lockout, no safe maintenance — this is OSHA territory, not preference. Used disconnects must have working lockout provisions (the hasp, the interlocked door); a safety switch that cannot be locked is not a safety switch. When selling: photograph the lockout hasp and confirm the door interlock works. When buying used: test both before trusting your life to them.
Heavy-duty fusible disconnects in common sizes (30–200A, 600V) are the steady sellers — every plant keeps spares. Value factors: amperage (bigger = more), fusible vs. non-fusible, NEMA rating (3R and 4X premium), and completeness (fuses included? fuse puller? mounting hardware?). Stainless 4X disconnects are premium units. Photograph the label (amperage, voltage, fusible/non), the interior with blades visible, and the enclosure rating. Like everything electrical: labels first, condition second, completeness always.
The code rule for motors: the disconnect must be rated at least 115% of the motor’s full-load current (NEC 430.110). For a 10 HP 480V motor drawing ~14A, that means a 30A disconnect minimum — and the common practice is the next standard size up. For non-motor loads, size to the load with the standard 125% continuous-load thinking. Horsepower ratings on heavy-duty disconnects are the shortcut: a disconnect HP-rated for your motor at your voltage is correctly sized by definition. When buying used: match or exceed the existing rating, never downsize — and verify the fuse class if fusible (Class R, J, or L rejection clips are not interchangeable).
To visibly open a circuit for safe servicing — and to provide lockout/tagout so only the servicing electrician can re-energize. Code requires one within sight of motors, HVAC, and major equipment.
Fusible holds fuses (protection + disconnect in one); non-fusible is just the switch. Fusible costs more and holds more used value.
Visible and not more than 50 feet from the equipment — so the person servicing the motor can see that the disconnect feeding it is open.
Heavy-duty fusible units in common sizes are steady sellers; stainless 4X are premium. Photograph the label, blades, and enclosure rating.
OSHA-required practice: the servicing worker locks the disconnect open with a personal padlock only they can remove — guaranteeing the equipment cannot be re-energized while they work on it.
Photograph the equipment, nameplates, and quantities in place, then send them through the contact form.
We review what the equipment is, its condition and quantity, and how it grades for resale versus recovery.
For qualifying material, we discuss a direct purchase offer and the next steps.
Manufacturer nameplates, breaker catalog numbers, panel schedules. Labels are the entire valuation.
Call or text 312-880-8174 or use the quote form.
A real offer based on your photos and today’s market — not a calculator, not a guess.
Breakers, panels, switchgear, transformers — send photos for today’s price.