JMS-F SunSpec Certified Rapid Shutdown Device Installation

by Trish Moratto (guest post), , 4 Comments
JMS-F SunSpec Certified Rapid Shutdown Device Installation

In this tech tip video, SMA Solar Academy Senior Technical Trainer Mike Mahon demonstrates the installation of the JMS-F line of SMA-compatible SunSpec-certified rapid shutdown receiver. These devices, when paired with the US-41 models of the Sunny Boy or CORE1 inverters, provide easy, reliable, module-level shut down to meet all the 2017 NEC rapid shutdown requirements.

For more information about commissioning the Sunny Boy US-41 click here.

For more information on installing the Sunny Boy US-41 click here.

 

4 Comments
  1. Avatar
    Jonathan says:

    With the installation of these rapid shutdown devices, can the SMA Secure Power Supply option still be included and function while remaining NEC 2017 compliant?

    Reply
    • Mike
      Mike says:

      Jonathan – The SunSpec transmitter in SMA inverters is configured to stop transmitting when the inverter loses AC power. This is done to allow any AC disconnect to serve as the Rapid Shutdown initiator. Use of the SunSpec shutdown does prevent the Secure Power Supply functionality of the Sunny Boy US line from working.

      Reply
  2. Avatar
    Greg S says:

    The shutdown module says it will not operate with less then 14 volts. Using 100 watt panels it may not enable the panel at times. Am I understanding that correctly? Why are 2 100 watt panels not able to be used with 1 device? Thank-you for your feedback.

    Reply
    • Mike
      Mike says:

      Greg – Please make sure you are looking at the most current datasheet The minimum voltage of the JMS-F device is 10V. It is possible that low voltage modules would be close to this voltage. SMA does not manufacture the JMS-F device, you can contact JMTHY to inquire if two series connected 100W modules could be connected to one device. Please note that the device power, voltage and current limits cannot be exceeded, and code limits voltage to below 80V within the array when Rapid Shutdown is triggered. So if the modules you are considering could have a Voc of over 40V each in the coldest temperatures, this setup would not be code compliant.

      Reply

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