Talk:DC injection braking/GA1

GA Review

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Reviewer: Pyrotec (talk · contribs) 20:53, 16 May 2012 (UTC)

I will review. Pyrotec (talk) 20:53, 16 May 2012 (UTC)

GA review – see WP:WIAGA for criteria

1. Is it reasonably well written?

   A. Prose quality:

   OK.

   B. MoS compliance for lead, layout, words to watch, fiction, and lists:

   The WP:Lead is intended to both introduce the article and summarise the main points. The Lead provides a good introduction, but does not summarise all the main points of the article. (The article is really too short, the Lead is almost 50% that of the body of the article).

2. Is it factually accurate and verifiable?

   A. References to sources:

   Only the Lead has references to sources: one source to be precise.

   B. Citation of reliable sources where necessary:

   None of the claims in the body of the article have any sources.

   C. No original research:

   Possibly not.

3. Is it broad in its coverage?

   A. Major aspects:

   The circuit diagrams shows half-wave rectified DC voltage applied to two phases of a three-phase motor, which is fine. The article itself has no discussions of single-phased and/or three-phased motors and whether this technique is equally applicable to both types, nor the method of producing the DC voltage. It claims simply without references that "the higher the voltage that is applied, the stronger the braking force and holding power", but it provides no discussion of the relationship between applied voltage and braking force / stopping power. Note: the circuit diagram clearly indicates that the DC braking voltage is obtained directly from two phases of the motor's normal running supply and will therefore be of a similar magnitude. There is no consideration of the stator heating that will result from a DC voltage braked motor (the fan-assisted cooling produced during normal operation will be absent), nor the noise/hum of applied DC voltage. Note: the module appears to have two adjustable circuits A and B which presumably control the start and finish of DC-voltage breaking. The article claims without references that friction brakes require actuation and add complexity to the system. Friction brakes have been used successfully for many decades: on domestic appliance such as spin driers, which have door interlocks, on industrial machines which have microswitches on access doors and/or emergency stop buttons, lathes (some of which have foot operated breaks); on large machines in which an electromagnet is used to override a spring-operated friction brake, killing the supply to the electromagnet allows the spring to close the brake. Standardised "DIN rail control modules", such as the one shown to provide DC braking, are presumably also available to provide electrical or pneumatic friction brake controls, and their incorporation into an AC motor's supply circuits appears to be no more complex than adding DC braking modules. Such claims that DC voltage braking control circuits are less complex than friction control brake circuits need to be supported with verifiable references.

   B. Focused:

   Somewhat over focused on the "claimed" benefits of DC voltage braking.

4. Is it neutral?

   Fair representation without bias:

   DC braking is merely claimed to be better and less complex that mechanical braking. Mechanical wear of brakes may be a valid point, but its also unquantified and unreferenced.

5. Is it stable?

   No edit wars, etc:

6. Does it contain images to illustrate the topic?

   A. Images are copyright tagged, and non-free images have fair use rationales:

   B. Images are provided where possible and appropriate, with suitable captions:

7. Overall:

   Pass or Fail:

   This article appears to be a cut-down version of the German-language wikipedia article [1], but with far fewer references and one fewer schematic diagram. The German article is unassessed. I consider that this particular article is Stub-class or Start-class (possible the latter) at most. So, I will not be awarding GA-status.

Pyrotec (talk) 13:29, 17 May 2012 (UTC)