What is base-can maintenance?
Looking after the buried housing under a light — the fixture lifted out, water and silt cleared, the drain, flange, grout joint and cable entries checked, and the fixture reseated on a new seal.
Base-can maintenance keeps the buried housing under a light dry, drained, undamaged and firmly set. With the circuit isolated, the fixture is lifted out and the inside is checked: water and silt, the drain, the flange, bolts and threads, the grout and pavement joint, the cable entries, and the connector and earth. The fixture is then reseated on a new seal and torqued, as in fixture installation.
Water is the usual enemy. Standing water around the connector can lead to insulation and earth faults, and it usually points to a cause: a failed seal, a cracked grout joint or a blocked drain. Clear it and find where it came from. If the can is cracked, loose or at the wrong height against the pavement, do not pack it or shim the fixture; report it for corrective work to the design. Check the bolts with torque checking. The circuit is live until it has been isolated, locked out and proved dead, and an energised series circuit must never be opened.
- Isolate. Switch off, lock out and prove the circuit dead before the fixture or connector is disturbed.
- Open. Lift out the fixture, keep debris out of the can and note what you find.
- Clean. Clear water and silt, check that the drain lets water leave, and clean the mating faces.
- Inspect. Check the flange, threads, can wall, grout and pavement joint, cable entries, connector and earth.
- Reseat. Fit a new gasket or O-ring, reseat the fixture and tighten to the specified torque.
- Test and record. Energise, check the light works and the can stays dry, clear all tools and log the work.
Frequently Asked Questions
Q1What is base-can maintenance?
Keeping the buried housing under a light dry, drained, undamaged and firmly set. It covers lifting out the fixture, checking the inside and the flange, the grout and pavement joint and the cable entries, then reseating the fixture on a new seal and torquing it.
Q2Why does water in a base can matter?
Standing water and silt around the connector and transformer can lead to insulation faults and earth faults, and they speed up corrosion. Water often points to a failed seal, a cracked grout joint or a blocked drain, so find where it came from as well as clearing it.
Q3Why must the drain be kept clear?
The drain lets water leave the can instead of building up around the connector. Silt, roots or a crushed pipe can block it. Check that water leaves freely, clear what blocks it and report a pipe that is damaged or does not fall away from the can.
Q4What is checked on the flange, threads and bolts?
Check the flange face for damage and corrosion, the threads for wear, and the bolts for condition. Clean the mating faces, fit a new gasket or O-ring each time as the manufacturer specifies, and tighten to the specified torque with a calibrated tool. Do not use unapproved sealant in place of the seal.
Q5What if the base can has cracked, moved or settled?
Do not pack it up or shim the fixture to cover the problem. A can that is cracked, loose, out of level or at the wrong height against the pavement needs corrective work to the design. Resurfacing and settlement can change the height, so check it against the design as well.
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