Read this first
This is a general reference for Miner Technicians — not a substitute for your site's official safety program, site-specific procedures, or OSHA-qualified training. Always follow your site's lockout/tagout, PPE, and electrical-safety rules. If anything is unclear or feels unsafe, stop and ask your supervisor.
Miners are high-voltage, high-current, hot, and loud. Most incidents come from electrical contact, arc flash, burns, or lifting. The habits below keep you and the fleet safe on the floor.
Electrical — the number-one hazard
PDUs, whips, and breakers carry 200–277 V and up (often 3-phase) at high current. Contact, arc flash, and arc blast can injure or kill instantly.
- Treat every circuit as live until it is proven de-energized. The miner LED means nothing.
- Only qualified, authorized technicians open panels, PDUs, or fixed wiring — know your site's rules on who may do what.
- De-energize and verify zero energy (test-before-touch) before working on anything hard-wired.
- Do not probe energized conductors as part of this curriculum. Electrical testing requires qualified, authorized personnel and the applicable safe-work procedure.
- No rings, watches, metal bracelets, or dangling tools near buswork.
- Never work on energized equipment in wet conditions or with wet hands.
Lockout / Tagout (LOTO)
LOTO keeps a circuit from being re-energized while you service it. It is a written, site-specific procedure — follow yours exactly.
- Isolate → lock → tag → verify zero energy before servicing breakers, PDUs, transformers, or fixed wiring.
- Apply your OWN lock and tag. Never remove or bypass someone else's lock.
- Only authorized persons perform LOTO. If you're unsure whether a task needs it, stop and ask.
- Verification of electrical isolation must be performed by a qualified person using the applicable procedure and suitable test equipment. A dark LED or stopped fan does not establish de-energization.
Hot surfaces & thermal burns
Exhaust air and heatsinks run 60–80 °C+; hydro coolant and immersion fluid can scald. A running or just-stopped unit is hot.
- Assume metal (chassis, heatsinks, fins) is hot. Let a unit cool or use heat-resistant gloves.
- Never crack a fitting on a hot, pressurized hydro loop — depressurize and cool it first; watch for steam.
- Route yourself away from direct exhaust when handling a running unit.
Immersion & hydro cooling
Dielectric fluid and coolant add slip, spill, pressure, and skin/eye-contact hazards on top of the electrical ones.
- Keep people away from spills and report them immediately. Do not approach liquid near potentially energized equipment; authorized personnel must establish safe conditions before cleanup.
- Wear gloves and eye protection when handling fluid; follow the fluid's Safety Data Sheet (SDS) for contact and disposal.
- Before fitting, bleeding, or removal work, authorized personnel must isolate the relevant electrical and fluid sources, control stored pressure and heat, and verify safe conditions under the equipment/site procedure. A stopped miner or pump is not proof of isolation.
- Keep the area ventilated and free of ignition sources per the fluid's SDS.
Noise
Mining halls routinely exceed 85–90 dB — loud enough to cause permanent hearing loss over a shift.
- Wear hearing protection (earplugs or muffs) any time you're on the floor.
- Take part in your site's hearing-conservation program and any required testing.
Lifting & mechanical
Air miners weigh ~13–16 kg (30–35 lb); hydro and immersion units are heavier. Racks have pinch points and sharp fins.
- Lift with your legs, keep the load close, and don't twist. Team-lift heavy or awkward units.
- Mind pinch points sliding units into racks; cut-resistant gloves help against sharp heatsink fins.
- Make sure units are fully seated and secured before letting go.
Heat stress
Hot aisles can hit 40–50 °C. Heat exhaustion and heat stroke are real risks during a shift of physical work.
- Hydrate before you're thirsty; take breaks in a cooler area.
- Report dizziness, cramps, or nausea promptly; stop exertion and move to a cooler area with assistance.
- Confusion, collapse, or altered mental state during heat exposure is an emergency: activate the site emergency response and local emergency number (911 in the US), begin safe cooling according to training, and stay with the worker until help arrives.
- Pace heavy work; don't push through symptoms.
Fire & housekeeping
High power density plus dust is a fire risk, and electrical fires need the right response.
- Keep aisles and exits clear; control dust buildup on and around units.
- Follow the site emergency plan: raise the alarm and move to safety. Only trained, designated personnel should attempt firefighting when safe, using the appropriate equipment. Never use water on energized electrical equipment.
- A burning smell, discoloration, melted connector, or smoke → de-energize if safe and report it immediately; do not re-energize.
PPE — bring the right gear
Match your protective equipment to the task and to your site's requirements.
- Safety glasses, hearing protection, and closed-toe/safety footwear on the floor.
- Cut-resistant gloves for handling boards and racks; electrical-rated gloves/tools for electrical work.
- Arc-rated clothing when working on or near energized electrical equipment, per your site's arc-flash assessment.
When in doubt, stop and ask. No repair, uptime target, or shift metric is worth an injury. This page is a starting reference only — your site's safety program is the authority.
