Noble M20 Dual, Installation Manual

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4.0 DNA Line Filter Specifications
Model Numbers
DNA Line Filters are given model designations, beginning with M. The number that follows the M
is the maximum AC current rating.
Examples:
M20 = maximum current 20 amperes 50/60 Hz
M30 = maximum current 30 amperes 50/60 Hz
M100 = maximum current 100 amperes 50/60 Hz
etc.
Model Letters
The model number may be followed by a letter if there is more than one model available for that
specific configuration.
Example:
M100a
M100b
The difference between the above-cited models (version a and version b) is the amount of
attenuation (the amount of DE reduction) that is available. In the above-cited example, the b model
has 4 times as much attenuation as the a model.
Other Model Descriptors
There are various descriptors that may follow the model number.
Examples:
The descriptor Dual may be used for a model.
Examples:
- A model
M20 can accommodate a single AC line phase (aka single Leg), at either 120 VAC or
240/250 VAC.
- A model
M20 Dual can accommodate two AC line phases (aka two Legs).
In the US in residental applications, a single phase is typically 120 VAC. Appliances that require
high power (e.g. electric clothes dryers, electric stoves, etc.) will typically be connected with 2
phases (2 Legs), where there is 240 VAC 60 Hz across these 2 phases.
The descriptor NEMA 3R may be used for a model.
NEMA (National Electrical Manufacturers Association) designation is used with the DNA Line
Filter products to indicate certain environmental capbilities. Specifically, NEMA 3R is a rain-proof,
snow-proof, sleet-proof, drip-proof enclosure. Note that is all of these environmental conditions, the
liquid is coming from above. NEMA 3R is not a “completely sealed” enclosure that will survive
being hosed.
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