The HXS-30 makes hydrogen and oxygen, takes a direct current of several hundred amperes, and has a corrosive electrolyte running through it. It is also far too heavy to lift by hand. The hazards come from several directions, and so do the safety rules.
A stack has no built-in safety functions. Detection, interlocks, overpressure protection and emergency stop all live in the system you build around it.
This chapter covers immediate safety actions only. Diagnosis is in the troubleshooting chapter, and that work happens after the area is secure and only by qualified people.
- HazardsHydrogen · high-current DC · electrolyte · weight
- PPEDepends on the task
- When to readAll of it, once, before installing
First timeThere is no section here to skip. Read it through once before installing, and keep the emergency response section next to the equipment.
Done this beforeRe-read the signal words and the emergency response. Use the rest when checking against your own site safety rules.
On this pageSignal words
Signal words
This handbook uses four signal words. They differ in severity, so read them as such.
| Signal word | Meaning |
|---|---|
| DANGER | A situation that will cause serious injury or death if not avoided |
| WARNING | A situation that could cause serious injury or death if not avoided |
| CAUTION | A situation that may cause minor or moderate injury if not avoided |
| NOTICE | Information that is not about personal injury but prevents equipment damage or loss of performance |
What this stack is for
The HXS-30 is for producing hydrogen and oxygen from an alkaline electrolyte, and nothing else. Operate it within the limits in this handbook and the datasheet.
Do not
- Run it on a different electrolyte
- Run it outside the current, voltage, pressure or temperature limits
- Modify its structure, or dismantle or repair it without authorisation
Who should work on it
This document is for system integrators who design their own BoP, power, control and safety systems, and for trained operators running the stack inside such a system. You should be familiar with four things.
- Hydrogen safety, and hydrogen and oxygen venting, ventilation and vent routing
- High-current DC power equipment and electrical hazards
- Alkaline electrolyte handling and chemical safety procedures
- Procedures for lifting and moving heavy loads
Hydrogen
- Operate only in a well-ventilated area, or connect the vents to an engineered exhaust system.
- Keep ignition sources away: no smoking, open flames, welding, grinding or spark-producing work near the stack or the vent outlets.
- Use electrical equipment suitable for the area classification where hydrogen may be present.
- Check for leaks by an approved method, such as a hydrogen detector. Never use an open flame to find a leak.
- Hydrogen collects at ceilings and other high points. Take that into account when placing ventilation and detectors.
Vent lines
- Vent lines must stay open. Fit no valve or device that could inadvertently close one.
- Do not restrict a vent line or create backpressure.
- Accumulated condensate can freeze a vent shut. Use slope, drain points, insulation or heat tracing as your site conditions require.
- An oxygen-enriched atmosphere raises the fire risk. Keep combustibles away from the oxygen discharge area.
Electrical
- All electrical installation is done by qualified personnel.
- Provide overcurrent protection and a disconnecting device to your local code.
- Earth the DC supply and all connected equipment properly.
- Never connect or disconnect power cables under load.
- Keep electrical components dry and protected from contact with electrolyte.
Electrolyte
- Handle it according to the SDS and your site procedures.
- Use only KOH-compatible materials, for containers, tubing and fittings alike.
- The loop holds a large volume of electrolyte. Provide secondary containment under the stack and the tank in case of a spill.
- On exposure, flush with water immediately and seek medical attention as required.
- Keep an eyewash station and a safety shower near where KOH is handled.
PPE
Safety glasses
Sealed goggles
Alkali-resistant gloves
Closed-toe shoes
| Task | Wear |
|---|---|
| Routine operation and monitoring | Safety glasses, closed-toe shoes and suitable work clothing |
| Handling electrolyte | Splash-proof goggles or a face shield, alkali-resistant gloves, and a chemical apron or lab coat |
| Lifting and moving | Safety boots and work gloves, plus whatever your site lifting procedure requires |
| Working directly on the stack | Safety glasses and work gloves. Near power cables and terminals, add electrical protection |
Emergency shutdown and response
A gas or electrolyte leak, an unusual noise, smoke, a nearby fire, or visible damage
- If it is safe to approach, stop the DC output to the stack and leave it off.
- Warn the people nearby, evacuate non-essential personnel and restrict access.
- Do not touch terminals, cables or wetted lines until the area is safe.
- Follow your site emergency response plan and notify the responsible safety officer.
- Do not resume operation until qualified personnel have identified and corrected the cause.
A hydrogen leak, or a suspected one
A spill or chemical exposure
What this chapter is based on
- HXS-30 datasheetPDF · 502 KB
- HXS-30 exterior STEP modelOn request
Ask the engineer who built it
If your case is not covered here, send us the operating condition and what you observed. The engineer who designed the system answers directly.