How to connect 12 (U-type) heaters each of 70.6 ohms in delta configuration to 380 V

How to connect 12 (U-type) heaters each of 70.6 ohms in delta configuration to 3-phase 380 V supply ?

thanx

Wire the 12 into 3 banks with 4 in each, these should be wired in parallel. Connect the banks to each other, so now you have three banks in series, wire the two free ends together. Now you have three positions where there are eight heater connections, connect each of these to a live phase.
Frank

This way..........

Please check the wattage of each element. For the above circuits each element would have to be 2045W

kak111 said:

This way..........
View attachment 66682

Click to expand...

Can we connect them in star configuration also ? If we can then what would be the effect on heating & on load & hence on power consumption ?

kak111 said:

This way..........
View attachment 66682

Click to expand...

How to control the heating of these heaters so that when we move the regulator (knob) from 0 position (off condition) to 1 position (heaters get on but heating is low) & at 2 position (heaters generate maximum heat) ?

Power & control diagrams are required ?

thanks

How to control the heating of these heaters so that when we move the regulator (knob) from 0 position (off condition) to 1 position (heaters get on but heating is low) & at 2 position (heaters generate maximum heat) ?

Click to expand...

Like this...........





KAK

what's the output power of these 12 heaters in delta configuration ? as heaters are the pure resistive loads

How can we connect tri-phase SSR with heaters & blowers ? Power diagram & controlling diagrams are needed also .......

the SSR is DC to AC SSR

The controlling is like that when we move the regulator (knob) from 0 position (off condition) to 1 position (heaters get on but heating is low) & at 2 position (heaters generate maximum heat) there is thermocouple connected with the heating unit which gives the feedback to the digital temperature controller, when temperature exceeds the set value (SV) the heating stops & blower (3 phase motor) starts to run ?

thanks

Can we connect them in star configuration also ? If we can then what would be the effect on heating & on load & hence on power consumption ?

Can we connect them in star configuration also ? If we can then what would be the effect on heating & on load & hence on power consumption ?

Click to expand...

Yes you can , then Power (delta) = 3 x Power (star) , Look post #7.....

what's the output power of these 12 heaters in delta configuration ? as heaters are the pure resistive loads

Click to expand...

Delta : Resistor voltage = 380V ; R = 70.6 Ohms then P one resistor is 2045 W >> Ptot = 12x2045W = 24.54kW

Star : Resistor voltage = 220V ; R = 70.6 Ohms then P one resistor is 686 W >> Ptot = 12x686W = 8.23kW

kak111 said:

Yes you can , then Power (delta) = 3 x Power (star) , Look post #7.....



Delta : Resistor voltage = 380V ; R = 70.6 Ohms then P one resistor is 2045 W >> Ptot = 12x2045W = 24.54kW

Star : Resistor voltage = 220V ; R = 70.6 Ohms then P one resistor is 686 W >> Ptot = 12x686W = 8.23kW

Click to expand...

How can we connect tri-phase SSR with heaters & blowers ? Power diagram & controlling diagrams are needed also .......

the SSR is DC to AC SSR

The controlling is like that when we move the regulator (knob) from 0 position (off condition) to 1 position (heaters get on but heating is low) & at 2 position (heaters generate maximum heat) there is thermocouple connected with the heating unit which gives the feedback to the digital temperature controller, when temperature exceeds the set value (SV) the heating stops & blower (3 phase motor) starts to run ?

thanks

This is simple manual 4-step On-Off Power Control wiring
for power preset, this can be added with temperature and
blower control.

when temperature exceeds the set value (SV) the heating stops & blower (3 phase motor) starts to run ?

Click to expand...

I think this is not good idea.
Doing so , the heating system control works like an oscillator and
and the temperature and and the heat energy moved to product is not stable

KAK

why did you use 4 sets of 3 heaters ? Why didn't 3 sets of 4 heaters ?

thanks

If you look at wiring diagram,
there is four three-phase SSR switch
each of them connect equal three-phase load ( load is symmetrical 3-phase all the time )
and four on-off push button each is given 1/4 power.
- 1 button down 1/4 max. power
- 2 button down 1/2 max. power
- 3 button down 3/4 max. power
- 4 button down = max. power
and 3-phase wiring can be connected star for 240V or delta for 400V load.

How can we distinguish that a motor is connected in star or in delta by viewing the terminal box of the motor ?

thanks

viewing the terminal box of the motor

Click to expand...

Check the motor nameplate too....
(2) Rated voltages in star & delta.



1. Manufacturer name and manufacturer-specific ordering code. This code will typically contain information about frame size and mounting arrangement.
2. Rated volts - The voltage at which the motor is designed to operates and give optimum performance.
3. Full load amps –.used to facilitate cable sizing, starter selection and motor protection.
4. Rated frequency in Hertz, and rated full load speed in revs/minute at that frequency.
5. Rated temp rise or insulation class – Industry standard specification of the thermal tolerance of the motor insulation.
6. Rated power (kW).
7. Electrical connection and associated operating parameters – i.e. three phase motors can be connected in a ‘star’ (Υ) or ‘delta’ (Δ) configuration. In a star configuration the current flowing from the supply is reduced as is the torque.
8. Power factor for the motor.
9. Efficiency class – IEC nameplates quote EFF ratings at full load. It is a measure of how well the motor converts electrical energy to mechanical power.

KAK