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Surge Protection

Other Parts Discussed in Thread: ULN2003B, TVS0500, TVS2200

Hi,

Good Day. I would like to confirm if the devices below can support 230V AC line surge protection for PWM Power Supply Unit.

https://www.ti.com/product/TVS1801

https://www.ti.com/product/TVS2201

https://www.ti.com/product/TVS1400

The PWM PSU is fitted with a TOP247YN Controller (per its datasheet to withstand a 700V surge and it failed to protect the PWM PSU, unfortunately) that was dematerialized during a thunder storm damaging other components down the circuit including AN2003B's among others. The PSU was protected with varistors that failed to do the job. If the devices above not fit on the query mentioned, My question is what would you suggest as a reliable protection against HV line surges. The line voltage is 230V AC as mentioned before.

Best Regards,

Ray Vincent

  • Hi Ray,

    Just to clarify, are you saying that the TOP247YN itself is being damaged by the surge, or it is failing to switch off fast enough to protect the other downstream components? Also, are the components being damaged on the AC or DC side of the transformer and rectifier? 

    Regards,

    Matt Smith 

  • Hi Matt,

    Good Day. Please see below the response of our customer to your reply. Thank you very much.

    I attached a shot of the damaged TOP247 due to line voltage surge as a result of lighting. Along that street 2 other gas boilers were damaged.
    The failed components include pulse transformer primary side (line voltage) TOP components, bias winding 4148 rectifier with 1uF/50V capacitor, optocoupler being part of feedback loop. On the secondary side of pulse transformer which provides 2 voltages 24 and 5V, 24V snubber cap failed and down the circuity 2 ULN2003B were also damaged. I cannot say anything of Microchip controller as I still have not brought the PSU back to life. As I said in my prior mail, varistor on the HV side (being AC 230 V) of PSU failed to protect the downstream circuity. Of course there is no schematic available yo my mind. This electronic controls have been made by SIT Controls B.V of the Netherlands but despite my efforts to contact them I cannot get hold of their contact person coordinates.
    I would appreciate if you could suggest a solution to my query and looking forward to hearing from you.

    Best Regards,

    Ray Vincent

  • Hi Ray,

    Understood. Unfortunately TI does not have any high voltage TVS diodes currently. The highest Vrwm we have is 33 V with the TVS330/1. I would recommend that your customer finds a 230 V Vrwm diode. It should be bidirectional if it is placed before the rectifier in order to handle the negative voltage swing. The datasheet of the TOP247 seems to have a few recommendations in their example applications. 

    However, if they want additional protection, they can put a TVS2200 and a TVS0500 on the DC outputs of the PSU to protect 24 V and 5 V outputs.

    Regards,

    Matt Smith 

  • Hi Matt,

    Good Day. Please see below the response of our query to your reply. Thank you very much.

    Could you please advise if the product linked below will fit my protection job.
    Thank you in advance for your support.

    Best Regards,

    Ray Vincent

  • Hi Matt,

    Good Day. I would like to follow up about latest query from the customer. Thank you very much.

    Best Regards,

    Ray Vincent

  • Hi Ray,

    I cannot speak for that product since it is made by STMicro. I would tell your customer to reach out to them for clarification. However, the breakdown specs suggest that it would be a likely candidate. 

    Regards,

    Matt Smith