I have a glycol feeder that sends liquids in to the hydronic system. This gycol feeder is held up by a steel frame which is isolated from the building. Does this steel frame need to be bonded?
When your not sure then "bond". It sounds to me like it does need to be bonded.
How ever more specifics would help. Such as what volts, amps , HP, ETC...
May be some one will chime in that has installed a machine like yours.