EXPLOSION-PROOF MOTOR STARTERS
We offer Ex d / Ex t Motor Starters in different configurations and with a variety of options.
All Ex d Motor Starters are provided with MANUAL RESET facility. Please note that "automatic reset" of overload protection devices is not deprecated in Hazardous Area installations (IEC 60079-14 Clause 7) and particularly for Ex Motor Protection (Clause 11.3.1): all our Explosion-proof Motor Starters are provided with electronic thermal protection relay and manual RESET pushbutton on the front panel. Loss-of-phase protection is also always provided as standard (trip on phase loss is within 3 seconds). Additional optional protections include Thermistor Overtemperature Protection, Ground Fault and Jam. The reset function for these additional protection is with the same RESET button on the front that mechanically resets the current overload relay. Network communication options include Ethernet, DeviceNet and Profibus.
Direct On-Line (DOL) Motor Starters
Standard DOL Motor Starters (commonly used for Fans and Pumps), with current overload protection up to 22 kW are available with fast delivery, in standard as well as in Self-Protected version with Type 2 Coordination (complete with incoming Circuit Breaker for short-circuit protection and isolation, with external padlockable operating handle). All Motor Starters are also provided as standard configuration with remote control connection facilities (for example to control the motor with Ex certified limit switches or float switches, or from another control station).
The engineering drawings below show the EJB1D3125 (up to 125A) explosion-proof isolator / protection circuit breaker, EJB1DOL22 Direct On Line Motor Starter and EJB2BCDOL22 Self-Protected DOL Motor Starter with Type 2 Coordination (withstands short circuit without damage) normally available for AC motors up to 22 kW. Higher power and / or other configurations can generally be manufactured with short delivery time.
Explosion Proof Reversible Motor Starters
Many practical industrial application require motors to be operated in both directions. Applications in Oli & Gas Processes that usually require Reversible Motor Starters include the control of Motor Operated Valves (MOVs), Gates, Lifts.
We can deliver Explosion-Proof Reversible Motor Starters in standard form or in various configurations to suit specific applications. The photo shows a Self-Protected 22 kW Reversible Motor Starter with IEC Type 2 short-circuit protection coordination.
Facilities for the connection of remote limit switches (which shall be Explosion protected or made Instrinsically Safe by means of appropriate and certified Barriers) are always provided.
Explosion Proof Star-Delta Motor Starters
The starting current of AC "squirrel-cage" three-phase motors driving loads not requiring high initial torque, indicatively six times the nominal current, can be reduced to about one third of the DOL current (two times the nominal motor current) using a "Star-Delta" starter. The starting torque is also reduced by a factor of three. The power contactors start the motor in a "Star" winding connection arrangement, and change over to the normal "Delta" connection after few seconds set by a dedicated timer.
Reduced voltage starters, such as Star-Delta Starters, are recommended for motor installations above few kW.
Explosion Proof Soft Starters
Soft Starters offer flexible control of the run-up time, current and torque, as well of the stop ramp. Today our Explosion-Proof Soft Starter solutions become more economical than Star-Delta options for power levels exceeding 22 kW.
We currently offer Ex d Soft Starter panels up to 132 kW motor rating. With the continuous progress of the Power Electronics technology, we keep designing new models with increased power rating, performance and features.
We provide Type 1 or Type 2 (Self-protected) protection in our Ex d Soft Starter solutions.
Double Motor Starters (e.g. for drilling rigs)
Some critical applications use two or more electric motors per each function. Mud drilling Rigs for example frequently have multiple Agitator Motors, Shakers, Pumps. As these motors are usually close to each other, it is advantageous to use double or triple motor starter solution. Two or more motor starters are built in the same enclosure, supplied from the same isolator (feeder disconnector). The motors are individually controlled and have individual overload protection.
Multiple Motor Starter solutions are integrated in Explosion-Proof Motor Control Centers or Motor Control Panels. We have designed and imlemented a range of integrated Ex d Motor and Power Control Centers for Drilling Rigs. These can include the protection of Light circuits as well as of other loads. See the Motor Control Panels page next for further information.