Energized Work Permit on a Chiller Feeder
You are a first-year apprentice. Site memo ESWP-07, issued by your contractor, reads in part: 'Energized work on any circuit operating above 50 volts requires a written permit signed by the project superintendent and the safety manager. A permit may be approved only where (a) de-energizing would introduce a greater hazard than the energized task, or (b) de-energizing is infeasible because of equipment design or operational limitations. Production schedules, customer preference, and the short duration of a task are not acceptable justifications. Work on circuits at or below 50 volts, and work on circuits that are locked out and verified de-energized, require no permit. Diagnostic testing that is part of normal equipment operation may be performed without a permit only when a qualified person uses listed test instruments.'
On Tuesday the chilled-water riser must be relocated. The 480-volt feeder to the chiller is the only source of cooling for a tenant data room, and the tenant has refused a six-hour shutdown. Your journeyman says the relocation will take about 25 minutes and hands you a permit form signed by the superintendent but not by the safety manager. Separately, a 24-volt thermostat control cable must be re-routed.
1. May the 480-volt relocation proceed energized? Identify the specific memo language that decides it.
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No. The circuit is above 50 volts, so a permit is required, and the permit on hand is incomplete - it lacks the safety manager's signature.
More fundamentally, no valid justification exists. The memo allows only two: (a) de-energizing creates a greater hazard, or (b) de-energizing is infeasible by equipment design or operational limitation. A tenant refusing a six-hour shutdown is customer preference, and the 25-minute duration is explicitly excluded ('short duration of a task'). Neither clause is satisfied, so the safety manager could not properly approve the permit even if asked. The work must be locked out and verified de-energized, or rescheduled - the memo names production schedules as unacceptable, and a tenant comfort shutdown is the same category of argument.
2. What does the memo say about the 24-volt control cable?
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No permit is required. The memo draws its line at 50 volts: 'Work on circuits at or below 50 volts … require[s] no permit.' A 24-volt control cable is below that threshold, so it falls outside the permit system entirely.
Note what the memo does not say: it does not declare low-voltage work risk-free, and it does not exempt it from lockout practice on the equipment feeding the control circuit. The 24-volt cable may be re-routed without a permit, but the panel or transformer supplying it still gets de-energized and locked out under the contractor's normal practice. Reading the exception narrowly - permit relief only - is the correct reading.
3. Your journeyman says to start on the 480-volt feeder because the superintendent already signed. What is the correct response, and what does the memo's structure tell you about why?
Read the worked answer
Decline and escalate. The memo requires both signatures, so a single signature is not a permit - the requirement is written as superintendent and safety manager, not either one.
The memo's structure also matters. Its two-part test (greater hazard, infeasibility), followed by a list of rejected excuses, is designed so the justification is examined before approval is requested, not after. A form signed by one party and justified by 'the tenant said no' fails at the justification stage, so the missing signature is not a paperwork problem to be worked around - it is a symptom that the approval should never have been requested in that form. State the memo paragraph, stop work on that feeder, and take the question to your supervisor rather than debating it on the lift.