2 - devices for industrial applications



The device controls the LINE, STAR and DELTA contactors for starting three-phase asynchronous motors of up to 25 Hp.

With this device, you do not have to add a thermal relay, transition timer, and monitoring ammeter. The Start and Stop pushbuttons are already installed and connected. The power LED and the motor ON LED are already mounted in the device, together with the other indicators needed for monitoring the operation. In the device are also mounted the contactor control relays.



Fewer components to install = lower cost - Extremely easy to connect = fewer mistakes - Lower connection and installation labour cost - Longer contactor life - Star to Delta changeover not time-dependent but tied to the actual motor run up. Start to delta transition problems during the critical phase eliminated - LED indicators for line- star- and delta-connected contactors, eliminating the bother of changing conventional indicator light bulbs- Current limiting indicator - Contactor control relays are not necessary since they are already installed in the device - The device is supplied with three copies of the circuit diagrams that can be easily filled out (average time 5 min.) and supplied to the final user as definitive documentation - Extremely simple to operate, the device can be used by staff not necessarily qualified to draw up project designs. In the documentation values for the contactor current and power are given for standard motors, 230 Vac and 400 Vac three-phase lines.


Smart startup sequence:

When the start pushbutton on the device is pushed, the line contactor gets energized. After 50 ms, the star contactor gets energized. 4" after reaching nominal motor speed, indicated by a corresponding decrease in current absorbed by the motor, the changeover from star to delta occurs. During the star startup phase, if the motor is undersized and thus not capable of achieving nominal speed, after a preset time, the motor will stop. In such cases, an indicator light will signal "Faulty star startup phase" "FAULTY". During normal operation in the delta configuration, should motor current absorption exceed the rated value, the device will stop the motor and an indicator light will signal the malfunction. The device will stop the motor if one phase fails (blown fuse, defective breaker, failure of one mains phase, broken motor winding, defect in motor wiring or in a part of the power circuit). All the phases have corresponding indicator lights (LEDs).


Technical specifications:

Size: 144 x 72 x P300 mm. Weight: 400 g. Enclosure: black polycarbonate. Pushbuttons: membrane with Omron micropushbutton. Indicators: LEDs, various colors. Power supply : 24/110/220/230 Vac 50/60 Hz. Power: 5 VA. Protection: internal fuse. Connectors: power supply + two TA + three potential-free connectors. Protection class: IP 44 (front panel). Certification: EC. Warranty: 12 months.



The device cannot be used for power values exceeding those shown in the table. The current values shown for motor models refer to standard motors. It is possible to adjust the value of the current by means of the trimmer located on the back of the control panel. This operation must be performed by qualified personnel, using a current clamp to check the actual power absorption of the motor.



Front control and indicator light panel

To access the interior of the device panel, insert a small flat screwdriver into the slots at the bottom of the panel and pry it open.

POWER: Power line ON.

L: Line contactor ON.

Y: Star contactor ON.

D: Delta contactor ON.

Y FAULT: Fault in star startup phase.

I MAX: Excessive current in the motor.

I LIMIT: Motor current threshold (performs the function of a thermal relay).

START: Motor start pushbutton.

STOP/RESET: Motor stop pushbutton - Alarms reset.


  Connection terminal block Motor power selection label



Terminal block connections
0 Vac
power supply
24 Vac
power supply
common line relay contact
line relay contact output (250 Vac 2 A) Max
star relay contact output (250 Vac 1A) Max
delta relay contact output (250 Vac 1A) Max
common star and delta relay output contact
TA1 input (see electric wiring diagram for connections)
TA1 input (see electric wiring diagram for connections)
TA2 input (see electric wiring diagram for connections)
12 TA2+ TA2 input (see electric wiring diagram for connections)




If, after selecting the correct DIP switch configuration, the star to delta changeover does not occur (this may depend on several factors such as excessive starting torque, etc.), the changeover current threshold can be increased.

Remove the instrument front panel, measure the DC voltage between the GND and Y bump contacts (factory setting: 10 Vdc), turn the P3 trimmer clockwise until the reading reaches 11 Vdc and try starting the motor. If the changeover still fails, it is likely that the selected motor is undersized with respect to the required startup torque. Check that the blade angle is correct. Also try selecting the dip switches for a motor size smaller than the actual one (for example, change from DIP switch 4 to DIP switch 3).


Operating principle:

According to the conventional star-delta startup method, the motor starts up star-connected and after a set time (selected depending on the size of the motor) the changeover to the delta-connection occurs. Unlike the conventional method, the CEI 2117B-C starter performs the star-to-delta transition when the current falls below the rated absorption value of the delta connection. This method is certainly better than the former, since during a conventional timer-controlled star-to-delta motor startup, the changeover could occur during the run up phase, possibly causing damage to the contactors.


Selecting DIP switches:

On both rows, turn ON the switches corresponding the motor size as shown in the device table. WARNING! Do not attempt to start up the motor without having first configured the DIP switches.


Startup procedure:

After setting the DIP switches, press Start. The board will energize the line and the star relays; when the current to the motor drops below the changeover threshold, the star relay will open energizing the delta relay. To stop the motor, press Stop.


- The motor starts up star-connected but after about 35 seconds stops and the "l FAULT" LED on the instrument panel lights up. Cause too much current during startup. Check using a current clamp. Solution see paragraph on settings and adjustments.

- While operating normally, the delta-connected motor suddenly stops and the "l LIMIT" LED on the instrument panel lights up. Possible cause Motor shorted out or current exceeding the nameplate value. Solution check wiring and motor windings.

- About 12 seconds after the start-to-delta changeover, the motor stops and the "l LIMIT" LED on the instrument panel lights up. Possible cause too much current when delta-connected. Solution For ventilators and air-exhausters check that the blade angle is correct; check the motor size; if needed, open the instrument by removing the front panel, check the DC voltage between GND and D bump contacts (factory setting: 11 Vdc); turn the trimmer P1 clockwise until the reading equals 12 Vdc and restart the motor.