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  1. kallileo

    RCBO tripping on generator

    @Parchie, waross I have attached the schematic of the connection. I understand in that order for the RCBO not to tripped the sum of all currents should be zero (L1+L2+L3+N=0). When there is a leakage bigger than 30mA the sum will not be 0 anymore and the RCBO will trip. But if the Neutral and...
  2. kallileo

    RCBO tripping on generator

    I have 3ph, 400V, 9kVA, 3000rpm air cooled generator on a trailer supplying a 3ph cooling unit (3phase compressor 2,2kW, 2 single phase fans around 0,2kW each and a 0,1kW single phase agitation motor) on the same trailer. I have installed a 4 pole RCBO, TYPE A, 10A, 30mA and bonded neutral and...
  3. kallileo

    Transformer for small DC Pump

    I have a 100W, 24VDC pump which I want to drive using an ssr and supply through a 230/24VAC transformer and a bridge rectifier. I have made a circuit using an AC SSR to supply/cut power to the transformer primary in order to turn on/off the pump. I have also installed a 1,25A fast blow fuse on...
  4. kallileo

    Grounding the secondary of a small transformer

    We have a small 230V device placed in a metal housing. We are going to display in an exibithion in US and in order not to modify it for 110V, we decided to use a 400VA 110V/230V transformer. Is it nessecary to ground the secondary of the transformer for safety reasons?
  5. kallileo

    Which DMM can you recommend?

    Check the Brymen. They are OEM manufactures and you can find rebranded Brymen DDM under many names like Extech, Greenlee.
  6. kallileo

    Mains voltage in US

    We want to make the machine as simple as possible so I want to avoid additional transformers. We are considering the 208/240V version for both heater and control circuit. The heating will be slightly slower when connected to 208V but it's will not be a problem. We can't find a circulator pump at...
  7. kallileo

    Mains voltage in US

    It's so much easier here in Europe. [bigsmile] The main concern is the heater. The standard heater is resistive 12KW wired in star connection for 3ph 400V. Practicaly they can be considered as 3 single phase heating elements of 4KW each.
  8. kallileo

    Mains voltage in US

    Our company manufactures pasteurizers and we want to make a US version. The standard european version uses 230V for the control circuit and 400V for the 3ph heater. Now we want to make a sample 120V/208V, 60Hz version. Live and neutral will be used to get 120V and the voltage between 2 phases is...
  9. kallileo

    MCB after or before relay

    Usually an MCB or fuse is place before the relay. What will change I place first the relay and after that the MCB like in diagram B?
  10. kallileo

    AC Line filtering

    I have installed a magnetostrictive level system on a tank in a farm and I have some problems. Since the voltage on the farms isn't stable and bad filtered during the milking when all the motors are on I get errors on the controller of the sensor. Possible cause is that the power noise isn't...
  11. kallileo

    1ph or 3ph VFD selection

    Does the drive provide thermal current overload protection or should a external device to be used?
  12. kallileo

    1ph or 3ph VFD selection

    I will not have any extra transformers. What does exactly the following means in the specifications? "Heat Loss at max output: 27W."
  13. kallileo

    1ph or 3ph VFD selection

    Eventually the motor will be 0,26kW and the drive ATCV2 0,37kW. http://www.inverterdrive.com/group/AC-Inverter-Drives-230V/Schneider-ATV12H037M2/ The drive has integrated EMC and a heat-sink but without a fan. I'm thinking on putting air vents on the box with some dust filters. According to...
  14. kallileo

    1ph or 3ph VFD selection

    Thanks for the input. There will be only one unit as this tank will be installed in a bakery. It's a nano size 1ph drive and it's easier to fit into the electrical panel of the tank than the 3ph model. Since it not going to have any influence the output torque negatively, I'm going with the 1ph...
  15. kallileo

    1ph or 3ph VFD selection

    I have a small agitation motor with the following charateristics: 230/400V 3ph50Hz 0.42/0.24A 100RPM Input Power 0,14W It will be used to agitate condensed milk in a vertical 400l tank. I will use a Schneider VFD to control the speed between 30-100RPM. The single phase ATV12 mode is 50%...
  16. kallileo

    Transformer output line protection

    So if I have a PLC in the same circuit do you think using coil suppresion will help?
  17. kallileo

    Transformer output line protection

    What about putting a varistor in parellel with the coil of each contactor?
  18. kallileo

    Transformer output line protection

    Low voltage isn't a problem. I'm sure about it. This machine (milk cooling tank) is an industrial products and we have manufactured hundreds of them. The valve coil and the compressor contactor's coil never operate simultaneously. This the first time I this kind of problem with the burned...
  19. kallileo

    Transformer output line protection

    Sorry I meant the terminals of the transformer and not the contacts of the contactor. The machine is located on a farm and the voltage there could be unstable and influnced by lighting. I just looks weird to me because there the coils of the compressors conactors were burned and no other 24Vac...
  20. kallileo

    Transformer output line protection

    I'm talking about fusing only the secondary of the transformer. Few days ago in the first panel, where the transformer is located, the secondary and the contacts were destroyed (burned) but I don't know the reason. Probably do some short circuit. It also destroyed 2 of the 3 contactor coils in...

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