| Electronics > Projects, Designs, and Technical Stuff |
| Power Control of Heating Elements |
| (1/1) |
| Regius:
Hi, I want to control the power of mains voltage heating elements with arduino. The total power of the heating elements is 12kW. At first i decided to make a three phase SSR with optrons and TRIACs because it is cheaper but now i think to skip this part and directly buy Commercial 3Phase SSR - at least it is designed professionally. I'm currently looking at this SSR https://www.tme.eu/Document/5bcacf8879a7a0f54111a99faa335ecc/SR3-series.pdf with Zero Cross Turn-On. With rough calculations the load current will be 12 000W / 220V = 55A or ~19A per phase - connected in Y configuration. 1. My first question is if the given rated Amps are for the whole SSR or for 1 phase (1 triac)? I suppose the given Amps are the total load current because otherwise it would be written "load current per phase" ... or something like that in the datasheet. 2. Is it a problem to control it directly from the arduino pin without any additional components? I see the input of the SSR is into an optron so there will be galvanic isolation between the arduino and the power circuit. Arduino output is 5V which is in the 4-30VDC limit of the SSR Input. 3. The arduino will be about 3-4m away from the SSR. Is it a problem for the 5V control signal from arduino? 4. What control interval (On/Off) will be OK? I'm thinking of 1 second interval. e.g. 10% power = 0.1s on / 0.9s off or 90% power = 0.9 on / 0.1s off Maybe to increase it? But lower than that i think won't be ok because the zero cross turn-on of the optron is not synchronized with the arduino output signal. I apologize if some of the questions seems stupid to you. I appreciate every answers / suggestions. |
| beanflying:
I am running a small Electric Coffee Roaster (3.5kW) off a glorified Arduino and software via a 40A SSR. There is a few problems with the Arduino PWM in that it doesn't like being run slowly and certainly wouldn't allow the use of mechanical switches or contactors. So part of the software/library was written into a slow PWM https://github.com/greencardigan/TC4-shield green cardigan is a member here but not that active. He is selling the TC4 shield on Tindie https://www.tindie.com/products/greencardigan/tc4-arduino-shield-v602/ Some of the original board info is here http://www.mlgp-llc.com/arduino/public/arduino-pcb.html Start here with some reading might help you along the way. Optical Isolation is a MUST !!! ;) |
| Regius:
I just use simple piece of code with a timer and counter which is turning on and off any of the outputs of the Micro controller. This is not okay for dimming a lamp but for the heater i don't think it will be a problem. I will read more about this slow PWM to understand how exactly it's controlling the SSR. |
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