birddogger
Electrical
Performed a walk-through of a facility to determine the condition/reliability of the electrical distribution system for a future tenant.
There are three 1000/1500kVA indoor dry-type substations, 13.8kV-277/480V substations, two of which are 29 years old. The transformer for the third SS is only 12 years old, while the switchboard and primary switch for that are both 29 years old.
The transformers, primary switches, and secondary switchboards (GE Power Break line) all appear to be in good physical condition. I do not detect any excessive humming to indicate loose windings. The transformers are quite underloaded since the prior tenant has vacated, but in a quick look at the downstream connected loads, it does not appear that any of the substations has ever operated near nameplate rating. All three subs are equipped with lightning arrestors. There is no known history of fault tripping on any of the feeders to indicate breaker wear. Antiquated but functional (and more importantly, still commericially available) GE Ground Break relays are installed on all feeders. Transformers have all been in continuous operation since prior tenant vacated, so there should be no moisture issues.
Two 1400 kW generators, both appearing to be in excellent condition (although extensive testing and maintenance log review will be recommended) are each connected to a switchboard with integral automatic transfer switches by Russ Electric. Generators and ATS’s are all also vintage 1975. Existing 5,000 gal. UG diesel tank could not be observed, will recommend checking to ensure code compliance.
For their part, GE has ensured that there should be no issues with spare parts and that from my description, it sounds like everything can stay for now. All indications are then that the gear is officially “ain’t-broke/don’t-fix”, but I want to recommend a certain level of testing to ensure reliability. The question is, to what extent should we test this equipment? I figure at a minimum we should have IR scans, a cleanliness check of the transformers, GFR testing, complete generator/ATS testing, testing of the MV switchgear, possibly vibration testing of the transformers. Does anyone have any other recommendations? Do I need to go to the extent of feeder insulation testing?
There are three 1000/1500kVA indoor dry-type substations, 13.8kV-277/480V substations, two of which are 29 years old. The transformer for the third SS is only 12 years old, while the switchboard and primary switch for that are both 29 years old.
The transformers, primary switches, and secondary switchboards (GE Power Break line) all appear to be in good physical condition. I do not detect any excessive humming to indicate loose windings. The transformers are quite underloaded since the prior tenant has vacated, but in a quick look at the downstream connected loads, it does not appear that any of the substations has ever operated near nameplate rating. All three subs are equipped with lightning arrestors. There is no known history of fault tripping on any of the feeders to indicate breaker wear. Antiquated but functional (and more importantly, still commericially available) GE Ground Break relays are installed on all feeders. Transformers have all been in continuous operation since prior tenant vacated, so there should be no moisture issues.
Two 1400 kW generators, both appearing to be in excellent condition (although extensive testing and maintenance log review will be recommended) are each connected to a switchboard with integral automatic transfer switches by Russ Electric. Generators and ATS’s are all also vintage 1975. Existing 5,000 gal. UG diesel tank could not be observed, will recommend checking to ensure code compliance.
For their part, GE has ensured that there should be no issues with spare parts and that from my description, it sounds like everything can stay for now. All indications are then that the gear is officially “ain’t-broke/don’t-fix”, but I want to recommend a certain level of testing to ensure reliability. The question is, to what extent should we test this equipment? I figure at a minimum we should have IR scans, a cleanliness check of the transformers, GFR testing, complete generator/ATS testing, testing of the MV switchgear, possibly vibration testing of the transformers. Does anyone have any other recommendations? Do I need to go to the extent of feeder insulation testing?
