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Stage 3 — Electrical acceptance

Controller and transfer-switch acceptance. Performed in the field after controller is installed and energized.

3.1 Controller listing — NFPA 20 §10.1.2 / NBR 16704 §10.2

3.2 Power source — NFPA 20 §9.2 / NBR 16704 §9.2

3.3 Automatic transfer switch — NFPA 20 §10.8 / NBR 16704 §10.8

Item Verified
ATS listed UL 1008
Transfer time ≤ 6 s normal-to-emergency
Transfer time ≤ 6 s emergency-to-normal
Re-transfer delay 5-30 min adjustable
Phase-loss detection on both sources
Engine-start contact wired to diesel controller (where applicable)

3.4 Phase loss / phase reversal — NFPA 20 §10.4.4 / NBR 16704 §10.4

Functional test:

Per NFPA 20 §10.4.4, phase loss must alarm but not prevent the controller from running on remaining phases — this is deliberate: in a fire, single-phase running for limited time is preferable to no pump at all.

3.5 Pressure switch / setpoints — NFPA 20 §10.5.2 / NBR 16704 §10.5

Standard cascade for a 100 psi (6.9 bar) rated pump:

Setpoint Pressure Action
Stop 110% × churn Main pump stops (if manual stop allowed)
Start, main 90% × system pressure Main pump starts
Stop, jockey 95% × system pressure Jockey stops
Start, jockey 85% × system pressure Jockey starts
Low-pressure alarm 75% × system pressure Alarm only

NFPA 20 §10.5.2.1 mandates manual stop for electric pumps (operator must press a stop button after at least 1 minute of running). The controller may NOT auto-stop on pressure recovery alone.

3.6 Emergency-run mechanism — NFPA 20 §10.5.3 / NBR 16704 §10.5

Mechanical override for control-circuit failure:

3.7 Diesel controller specifics — NFPA 20 §12 / NBR 16704 §12

Where pump driver is diesel:

3.8 Sign-off

Field Entry
Electrical contractor _________
Field engineer _________
Controller serial number _________
Date of test _________
Items 3.1-3.7 verified ☐ Yes ☐ No (list exceptions)
Authorization for AHJ acceptance scheduling ☐ Yes ☐ No

Next stage: Documentation package review.