Explosion Proof Direct Online (DOL) Starters
For fixed-speed motor applications in classified hazardous areas pumps, fans, compressors, and conveyor drives explosion proof Direct Online (DOL) starters provide the simplest, most reliable, and most cost-effective motor starting solution. Team Switchgear and Control LLC manufactures ATEX and IECEx certified Ex d DOL starters in Dubai, engineered specifically for Zone 1, Zone 2, and Division 1/2 installations across UAE and GCC Oil & Gas and Petrochemical facilities.
A Direct Online starter connects the motor directly to the supply voltage, providing full voltage starting torque from the moment of energisation. In a hazardous area, the starter assembly including the contactor, overload relay, pushbuttons, and all wiring terminations must be housed within a certified flameproof (Ex d) enclosure that prevents any arc or spark inside the panel from igniting the surrounding explosive atmosphere.
Our Ex d DOL starters are built into BARTEC-certified flameproof enclosures, populated with Siemens or Schneider Electric contactors and thermal overload relays, and wired with certified Ex d cable glands. They are available in standalone or grouped configurations, with local start/stop pushbuttons and running indication lamps integral to the enclosure.
Standard Features
- BARTEC certified Ex d IIB+H2 or IIC flameproof enclosure as standard
- Siemens SIRIUS or Schneider TeSys contactors ATEX/IECEx rated
- Manual motor starter or bimetallic thermal overload relay adjustable trip current
- Integral Ex d local start/stop pushbuttons and run/trip indication
- Earth fault relay option available for isolated neutral systems
- Phase failure and phase sequence relay option
- Emergency stop mushroom-head push-button, red, IP66, Ex d rated
- Motor circuit breaker (MCB) or fuse-switch-disconnector upstream protection
- 316L stainless steel or powder-coated RAL 7035 enclosure standard or custom colours
- 100% FAT including insulation resistance, continuity, and functional test
Sizing and Motor Ratings
| Motor Rating | Contactor Frame | Full Load Current | Enclosure Size |
| Up to 7.5 kW | S00/S0 (9–25A) | Up to 16A | Small Ex d box |
| 7.5–22 kW | S2 (32–50A) | Up to 45A | Medium Ex d box |
| 22–55 kW | S3 (65A) | Up to 110A | Large Ex d box |
| 55–110 kW | S6/S7 (115–160A) | Up to 200A | XL Ex d enclosure |
| Above 110 kW | Soft starter / VFD solution | Ex p purged panel |
When should I use a DOL starter versus a soft starter or VFD in a hazardous area?
DOL starters are ideal for fixed-speed motors up to approximately 75–90 kW where high inrush current at start is acceptable for the network and the driven equipment can tolerate full-voltage starting torque typical for centrifugal pumps, fans, and small compressors. For applications requiring soft starting to reduce mechanical shock (e.g. reciprocating compressors), or variable speed for process control, a soft starter or VFD panel with Ex p purging is the correct choice. Our engineering team can advise based on your motor size, load type, and network characteristics.
Can you supply Ex DOL starters with ATNOC-approved components?
Yes. We have experience designing and supplying panels for ADNOC-approved projects and can select contactors, overloads, and enclosures from the approved vendor lists of major UAE operators. Documentation packages including Material Data Reports, third-party inspection certificates, and Ex Q-files are available.
