From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
General table and suggested limits for relay switch gaps of a main and relay switch unit.
| Identifier | ExFiles\Box 64\3\ scan0213 | |
| Date | 9th March 1926 | |
| X7650 9.3.26. GENERAL TABLE FOR RELAY SWITCH GAPS. X8650 (Main and relay switch unit). Position. | Gap on upper contact. | Gap between pole core & armature. | Gap on lower contact. | Gap at carbon contacts. ---|---|---|---|--- Off. | O | A + B | δ B | -EC Carbons in contact. | C | A+B-C | δ (B-C) | O On. | B | A | O | E (B-C) TABLE OF SUGGESTED LIMITS ACCORDING TO THE ABOVE RELATIONS. Position | Column 2 | Column 3 | Column 4 | Column 5 ---|---|---|---|--- Off | | .042+8-6 | .053+10-5 | -.040+10-0 (Depression). Carbons just making. | .018"+5-3 | .025+10 | .021+15 | O On. | .030+5-3 | .012+3 | O | .027+20 EFC. | ||