Transformers with features not listed in FAA AC 150/5345-47A cannot be FAA certified and therefore this requirement should not be included in your specification. This would include:
• All earthed (grounded) transformers
• Ratings such as 150W, 400W
The FAA limit is 20 micro amps, which may have been appropriate when this specification was written, but is unnecessarily high for today's state-of-the-art transformers.
