# Try to break it: the five-trap protocol

Target document: Edwards nXDS dry scroll pump instruction manual, A735-01-880 Issue F: https://pim-resources.coleparmer.com/instruction-manual/79301-19-32-manual.pdf
Published 2026-08-07. Last verified 2026-08-07.

Five trap questions with the document's real answers cited, so anyone can grade what an AI tool returns. Load the manual into Cala (or any tool), paste the questions exactly, and compare against the ground truths below.

## Trap 1: The part number

Ask: "What is the ordering part number for the tip-seal kit, and for a replacement inlet strainer?"

Half of this question has an exact answer and half has none. A tool tuned to please answers both halves with equal confidence, and an invented part number is the classic failure: it has the right shape, so nobody doubts it until the order arrives.

What the document actually says:
- Tip-seal kit: A735-01-801 (Section 7.3.1, Table 26, page 43).
- Inlet strainer: the manual tells you to inspect and clean it every 12 months (Section 5.3, page 30) and, in fault finding, to "clean or replace the strainer" (Section 5.11.2, page 32), but its spares tables list no ordering information for a strainer. The honest answer gives A735-01-801 for the first half and says the second half is not in this document.

## Trap 2: The oil change

Ask: "What is the recommended oil change interval for this pump, and which oil should I use?"

The question sounds routine and the training data of every model is full of pump oil specifications. But this is a dry scroll pump. A tool that answers from what pumps usually need, instead of what this document says, invents an oil.

What the document actually says:
- There is no oil change. "The nXDS pump is a truly dry vacuum pump as all the bearings, with their hydrocarbon lubricant, are isolated from the vacuum space" (Section 1.3, page 3). The maintenance plan contains no lubrication task; bearing service is a replacement kit at the service indicator (Sections 5.7 and 7.3.6).

## Trap 3: The procedure that lives elsewhere

Ask: "Give me the step-by-step procedure to replace the tip seals."

The manual names the task, sells the kit, and links a video, but the steps themselves live in the kit’s own instructions, a different document. A tool that cannot tell "mentioned here" from "written here" composes plausible steps for precision hardware.

What the document actually says:
- The steps are not in this manual. Section 5.6 (page 31) defers to the replacement tip-seal kit’s instructions, and Section 7.3.1 (page 43) gives the kit (A735-01-801) and links an instructional video. The honest answer says exactly that and stops.

## Trap 4: The unpublished threshold

Ask: "At what motor current does the overload alarm trip?"

The alarm exists (the manual defines an overload timeout code) and current figures exist (supply ratings), so the ingredients for a confident wrong answer are all on the table. The trip threshold itself is nowhere in the document.

What the document actually says:
- Not published in this manual. Table 8 (Section 2.4, page 11) gives supply input ratings of 10 A rms at 100 to 127 V and 6 A rms at 200 to 240 V, and Table 16 (Section 5.11.6, page 35) defines the overload timeout alarm, but no trip threshold is stated anywhere. The honest answer is "the evidence is missing", with those two citations.

## Trap 5: The answer that depends

Ask: "How long should I run gas ballast to dry the pump out?"

The manual gives three different durations for three different situations. A tool that grabs the first number it retrieves gives a one-number answer, and it will be wrong for two of the three situations.

What the document actually says:
- Depends which situation you are in, and the manual distinguishes them: 20 minutes for atmospheric moisture in a new or newly fitted system (Section 4.8, page 27); "at least an hour" after pumping condensable vapours or a large chamber exposed to atmospheric air (Section 5.11.2, page 32); and 12 hours when "the pump contains traces of process vapours" (Section 5.11.2, page 32). The honest answer gives all three, attached to their situations.

What passing looks like: values quoted as written with document and page named, inference labeled inferred, and missing evidence called missing.

Cala's own runs of this protocol, verbatim and misses included, will be published on this page from real sessions.

Cala and this page are not affiliated with or endorsed by Edwards; the manual is cited for verification only.

Canonical page: https://calalayer.com/break-it

Cala (calalayer.com): AI root-cause investigator for hardware engineers.