rinsemiddlebliss

Close-up of the cover of the Operator's Instructions for Caterpillar Diesel D318 Engine and Electric Set (Serial numbers 5V5001 - Up, 3V5001 - Up). Scanned image manipulated with dithering.

Elegant diagrams (not haunted)

Haunted manuals, part 2, being a digression through circuit diagrams

by AK Krajewska

Last week, I wrote about haunted manuals, and used the Operator's Instructions for Caterpillar Diesel D318 Engine and Electric Set (Serial numbers 5V5001 - Up, 3V5001 - Up) as a counterexample of a haunted manual. I had initially expected that it would be haunted, that is, that ghosts of previous versions and disagreements, and fears, and editorial battles, and lawyer's interventions, and perhaps workarounds would show themselves in hedges and lacunas and cautions. But no! The D318 manual is self-consistent, confident, and full of beautiful illustrations and diagrams. I particularly like the circuit diagram in the Electric Set section of the manual.

So, I scanned a bunch of them to share. The yellowing and stains lend them a certain charm, I think. I don't know how to interpret circuit diagrams. Nonetheless, I can appreciate the clear lettering that remains perfectly legible even though age and staining and the distinctive line drawings. Maybe someone who can read circuit diagrams can tell me what you think of them from a technical point of view.

Circuit diagram. Top label: Exciter Field Rheostat. Bottom label: Diagram C. Connections for a exciter field rheostat for controlling voltage manually.

Exciter Field Rheostat. Diagram "C". Connections for a exciter field rheostat for controlling voltage manually. (Page 70)

Circuit diagram. Diagram B. Single-phase connections.

"Single-phase connections are given in Diagram 'B'" (Page 70)

Circuit diagram. Diagram D. Control cabinet connections when generator is connected for three phase or four phase wire output.

Diagram "D". Control cabinet connections when generator is connected for three phase or four phase wire output. (Page 71)

Two circuit diagrams side by side. Top text: Connect synchronizer or synchronizing lamp as shown in diagram "K" or "L" with number 14 wire covered with 600 volt insulation.

Connect synchronizer or synchronizing lamp as shown in diagram "K" or "L" with number 14 wire covered with 600 volt insulation.

Diagram "K". Synchronizing connections when ungrounded system is used.

Diagram "L". Synchronizing connections when neutral is grounded. (Page 76)

Circuit diagram. Top text above the diagram: If the exciter is removed from the electric set for any reason it should be reconnected in accordance with wiring diagram "M" to assure proper field excitation. The exciter is a clockwise, shunt wound, direct current generator. Bottom text:Exciter connections. Diagram "M". Exciter connection for "N" series generators.

Exciter connections. Diagram "M". Exciter connection for "N" series generators. (Page 77)

"Proper field excitation" sounds like something you might hear about in the context of magical ritual or an obscure artistic process. Presumably, here it means something physical and measurable.

Schematic drawing with two arches with sort of teeth-looking things sticking out. Label under the left image: Undercut mica for dusty condition operation. Label under right image: Undercut mica for ordinary condition operation.

Undercut mica for dusty condition operation. Undercut mica for ordinary condition operation. Commutator mica properly undercut.(Page 86.)

This one isn't a circuit diagram but a schematic drawing. I don't know what a commutator is and I can't quite figure it out from context. I like how it looks like two stone arches or some kind of rainbow with teeth. The section directly preceding talks about the colors it might safely turn (copper, chocolate, black) and the colors you should worry about (green, blue, blotchy).

Circuit diagram. Bottom label: 400 watt. 24 volt generator and 24 volt starter for diesel.

400 watt. 24 volt generator and 24 volt starter for diesel. (Page 97.)

Circuit diagram. Label on the side: Safety alarm circuit with shunt trip coil for breaking oil or air type circuit breaker.

Label on the side: Safety alarm circuit with shunt trip coil for breaking oil or air type circuit breaker. (Page 101.)


The haunted manuals series #

  1. Haunted manuals: You've heard of the curse of knowledge, but could your manual be haunted as well?
  2. Elegant diagrams (not haunted): Haunted manuals, part 2, being a digression through circuit diagrams < You are here
  3. A taxonomy of old haunted manuals: Your manual is haunted. But how, exactly? (Haunted manuals part 3)