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Camtec Introduces New 3rd Generation And Cost-Effective Inrush Current Limiter – Distributed by IBS Electronics Group


Thursday, January 9, 2020

Camtec Power Supplies banner image.

General Information

The CAMTEC ESB303 is the 3rd generation and cost-effective inrush current limiter. The limiter is designed for 200-240Vand can be operated in a 3x400Vac 16A networks with a neutral conductor. The ESB303 can either be used as 3-channel single-phase ESB or as a 3x400Vac ESB. Each phase connection allows to connect 6000uF capacitive load. It is necessary to connect the Neutral conductor to the ESB to let the device operate. The PE conductor must not be connected to the ESB303. The line frequency range is 161⁄3Hz – 440Hz. The ESB303-Limiter shall be located between the line- switcher/contactor and the load.

The ESB-models are designed for capacitive loads (not for inductive loads like coils/transformers, not for AC-motors and not for DC-voltage application). In the moment of switching-on the system the inrush current of the installed load will be limited for the defined time Ton . Independent from the previous inrush level; the current limiting is always strict. After Ton elapses the current limiting circuit of the ESB303 will be bypassed. Then the load is directly connected to the AC. The electrical network can be stressed with current loads as normal (e.g. motors, pumps). If an AC dump overshoots the defined time Toff, it will be detected by the ESB303. As soon as the AC recovers the inrush will be limited, again. The ESB303-models provide an internal temperature control. In case of a failure the device shuts down to safely prevent from overheating or fire. The power consumption of the unit is <3,3W (<3×1,1W per phase conductor at 230Vac)

The ESB303 is a budget-priced inrush peak current limiter for high loads in LED- applications, complex automation systems and in the machine building. The ESB303 offers effective and interference free operation with capacitive loads. It is simple to integrate into existing equipment. The ESB303 is self- powering and does not require an external power supply.

View Camtec ESB303 Data Sheet   Download

Short Specification:

    • Peak- / R.M.S. current limiter
    • 3×200-240Vac or 400Vac
    • DIN TS35mm DIN-Rail
    • Wall mount (universal housing)
    • Spring-type terminals 0,5-6mm2 / 21-10AWG
    • Integrated bypass relay
    • Capacitive load 6.000uF per phase conductor
    • Integrated over temperature protection
    • IP20 UL94V-0 housing DIN43880for DIN/VDE0603 cutout box

Camtec ESB303 features.

Camtec ESB303 technical specifications.

Field Applications

The ESB303 limiter allows connecting much more capacitive loads (e.g. LED-power supply / LED-driver) to a pre-installed circuit breaker CB. The ESB avoids that the MCB will be tripped. This occurs independent to the objective initial current. The result is that the number of A.C. branch lines and the pre-installed MCB can be reduced dramatically. Installation cost exhibit a sustained decline. Alternatively, the cross section of the branch lines can be reduced when using smaller and faster responding circuit breakers. The cost saving from copper is essential. Sensitive AC networks can be fused safer (e.g. Traffic Control Systems, Street-Lighting, Parking Lots and Tunnels). When the ESB303 is installed correctly, the neutral wire (N) is looped trough. The inrush protection circuit always acts to the line conductor. The load relates to the AC in such a way that a circuit breaker or an earth-leakage-trip works within the limits of the legal rules. This fact is also applied while the limiting circuit acts. The ESB303 is designed for capacitive loads, only. The ESB303 cannot be used together with transformers, coils, AC-motors & drives, heaters or with DC-voltage at all.

Design-In of the ESB303 into A/C networks

The ESB303 model is a precise inrush current limiter with an overall tolerance of ±6% of the face value. For the dimension of an upstream connected circuit breaker the R.M.S is the key value of the inrush current, not the peak current. The thermal trigger point will not be met, even while using an extreme fast CB. All-dominant is the magnetic trigger current. By using the empirical formula I(peak) x 0,707(factor) = I(r.m.s.) the tripping current can be defined exact. Bear in mind that all the higher the inrush current is, all the faster the input capacitor of several connected switch mode power supplies will be loaded. Deduced by this fact we can say that within a 230V or a 400V 16A A/C N-wire network the ESB303.LED.200/400V limiter is the right selection for a B13A 10kA or a B16A MCB 10kA. The technical table on page 2 shows the R.M.S value of the ESB303. Do not use an MCB that has a larger value than 16A.

Schematics of possible installation variations using the ESB303.


IP20 housing, UL94V-0 ABS with RTI 85°C, housing for DIN/VDE0603 cutout box and wall mount. DIN 43880 with IEC standardized ventilation slots. Save fix on DIN-Rail TS35mm (7.5/15) DIN/EN60715. It is designed for building cabinets DIN/VDE0603. Easy to wall mount by multifunctional housing; remove the DIN-Rail latch and access the two mounting holes to screw the ESB303 to any flat surface.

Camtec ESB303 dimensions.

Mounting Instructions

Follow the mounting restrictions to allow maximum lifetime of the product and to prevent from tripping the internal temperature protection fuse. The ESB303 is an active device. The distance between an ESB303 and the next active or temperature sensitive device shall be 17,5mm. To a non-active device, the distance can be 0mm. The power consumption of the device is 3.3W (3×1.1W per phase conductor) constant at 230Vac continuous operation. Make sure that the ventilation holes below and above the unit are not blocked to allow free air convection. The neutral must be connected to the device. If the neutral is not connected the ESB303 remains in the limiting mode. If so, the device will overheat, and the internal temperature protection will irreversible blow.

Camtec ESB303 temperatures.

The distance between an ESB303 and the next active or temperature sensitive device shall be 17.5 mm.

The distance between an ESB303 and the next active or temperature sensitive device shall be 17,5mm. To a non-active device, the distance can be 0mm.

Camtec ESB303 table of standards compliance.

Where to buy?

Since 1995 Camtec has been a leading German supplier of demanding power supply systems, distributed by IBS Electronics.

IBS Electronics is an ISO 9001: 2015 certified authorized franchise distributor and a global leader in the delivery of innovative electronic components and logistic solutions. For more information or to Request a Quote, please Contact IBS Electronics.

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