HomeTechnical notes › How to Select Explosion-Proof Electrical Control Boxes: Explosion-Proof Selection of Pushbuttons, Indicator Lights & Switches

05 Informational content / Technical articles 2026-09-11 Published ~ 11 min read GB 3836.1

How to Select Explosion-Proof Electrical Control Boxes: Explosion-Proof Selection of Pushbuttons, Indicator Lights & Switches
Explosion-Proof Operating Elements

Every push of a button and every lit indicator is a potential ignition source— an explosion-proof electrical control box (operator station / pushbutton box) puts an explosion-proof enclosure around these small components. Small as they are, they are the most frequently operated and most frequently damaged explosion-proof devices on site. This article follows GB 3836.1 to explain the selection points for explosion-proof pushbuttons, indicator lights and selector switches. Zhejiang Golden Unicornoffers joint supply with an Ex-qualified manufacturer, holds ISO 9001:2015,MOQ 1 unit · 15–25 days.

1. What Is an Explosion-Proof Electrical Control Box? (Operator Station / Pushbutton Box)

An explosion-proof control box, also called anexplosion-proof operator station, houses pushbuttons, indicator lights, selector switches and ammeters in a flameproof enclosure and is mounted next to the controlled equipment (motor, valve, pump) to providelocal start/stop and status monitoring. Difference from a control cabinet: the control box is the on-site operating end, while the control cabinet is the logic hub; the two work together.

SCHEMATICBusbarsTerminal blocksMain circuit breakerControl & protection devicesTerminal block outgoing cables
Figure — 1. What Is an Explosion-Proof Electrical Control BoxCabinet structure diagram · photo pending

2. Explosion-Proof Pushbutton Selection (Contacts and Operating Head)

ParameterCommon specificationsWhat it should show
Rated currentAC 220V 5–10ADirectly drives contactor coil
Contact configurationFrom 1 NO + 1 NCStart 1NO / Stop 1NC
Operating headMushroom head / round head / illuminatedEmergency stop must be mushroom head + latching
Actuator rod transmissionFlameproof operating mechanismButton force is transmitted through the flameproof shaft

Emergency stop pushbuttons must use ared mushroom head + latching (twist-to-reset), a dual requirement of GB/T 3836.1 and ergonomics.

3. Explosion-Proof Indicator Light Selection (LED preferred)

4. Explosion-Proof Selector Switch and Ammeter (multi-function operation)

Selector switch: the handle drives through a flameproof shaft, with positions such as Manual/Stop/Auto and Local/Remote; contacts sit inside the flameproof chamber.Ammeter: a pointer meter mounts behind a flameproof viewing window, or choose an intrinsically safe digital meter head (with CT). When selecting, note theoperating frequency— switches operated frequently need larger contact ratings, otherwise contact erosion raises contact resistance and heat buildup worsens.

SCHEMATICBusbarsTerminal blocksMain circuit breakerControl & protection devicesTerminal block outgoing cables
Figure — 4. Explosion-Proof Selector Switch and AmmeterCabinet structure diagram · photo pending

5. Five Key Selection Points (one checklist covers it all)

  1. Area and marking: Zone 1 Ex d Gb; Zone 2 may use Ex e/Ex n.
  2. Component list: number/color of pushbuttons, number/color of lights, switch positions, whether a meter is included — list each item against the operating procedure.
  3. Cable entries: size the number and diameter of entries to the number of control cables (G1/2 is the most common).
  4. Mounting: pedestal-mount / wall-mount / cable tray-mount; operating face height 1.3–1.5 m.
  5. Protection: outdoor IP66; on vibrating equipment, reinforce the mounting to keep the flameproof joint from working loose.

FAQ FAQ

What is the difference between an explosion-proof control station and a control cabinet?

The control station is thefield operating interface(pushbuttons/indicator lights); the control cabinet is thelogic hub(contactors/PLC/protection). The control station is usually mounted beside the equipment; the control cabinet sits in the electrical room.

Why must an emergency stop button have a mushroom head?

The mushroom head has a large surface, is easy to slap, and latches to prevent accidental reset. At the moment of an accident, itsstrike reliabilityis far higher than a small round-head button — it is a mandatory requirement.

Can I make my own acrylic lens if the indicator light cover cracks?

Absolutely not. The lens cover is part of the flameproof structure; a homemade part has no certification and does not meet thickness or material requirements — you must replace it with an OEM part.

Can a burned contact on an explosion-proof pushbutton be repaired?

The actuator head and contact block can be replaced with OEM parts per the manufacturer's service manual (GB/T 3836.13 repair requirements). After repair, flameproof parameters must be re-verified and documented.

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