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What type of feeder outage will a Load Operator be most concernedwith?
Forced Outages (Sustained Outages) – system component failure, disturbances, emergency conditions will require proficiency by the Load Operator to identify and respond to restore customers as quickly as possible
What are the most typical causes of feeder faults?
- Transient, or temporary faults occur most typically.
- -With Reclosing in effect service is often restored immediately
What should a Load Operator suspect as the possible cause of asustained feeder fault when there has been no report or evidence as tothe cause of the fault?
- This scenario is usually due to the failure of the feeder cable
- -opening the field pothead switch and attempting to test energize the feeder cable is the normal practice to confirm this
What are some typical causes of substation equipment outages?
- -internal faults within a transformer, voltage regulator, reactor
- -capacitor bank failure
- -circuit breaker or disconnect failure
- -underground cable sections within the substation
- -protection misoperating (sometimes by personnel)
What has BC Hydro done within their substations to help preventanimals and birds from causing equipment outages?
Animal and bird guarding equipment has significantly mitigated nuisances from animals
Where is BC Hydro’s feeder reclosing policy documented?
DOO 1D-51 (Distribution Substation Feeder Reclosing Policy)
How long does a Load Operator have to attempt a manual reclose on afeeder circuit breaker following a trip?
Within 60 seconds of initial trip
How can a Load Operator determine if reclosing is permitted on agiven feeder circuit?
- On the EMS display, an X inside the CB display indicates reclosing NOT permitted
- -All other CBs are reclose permitted (As per 1D-51)
Where is BC Hydro’s distribution substation bus reclosing policydocumented?
SOO 1T-29B (Distribution Substation Bus Reclosing Policy)
How can a Load Operator determine if bus reclosing is permitted at agiven substation?
- Underneath the station nameplate in SCADA, there will be text:
- ‘FEEDER BUS RECLOSING IN EFFECT’
- Otherwise, there will be text:‘DO NOT RECLOSE’
What is cold-load pickup?
- The loading imposed on the distribution system following a prolonged service interruption
- Depending on the connected load, re-energization could cause nuisance operation of protective devices
- **the transient inrush of motor starting and transformer magnetizing current and the enduring demand as a result of loss of diversity**
- --essentially the inrush of current of every device magnetizing and coming on load can pull voltage down-
When is a feeder outage considered to be momentary and when is afeeder outage considered to be sustained? What are the LoadOperator’s responsibilities in terms of reporting?
- Momentary outage = 60 seconds or less
- Sustained outage = 60 seconds or longer
- - co-ordinate resources to ensure they are effectively used for speedy restoration
- - inform Day Shift manager or SCM of outage
- - DOO 1D-10 (Distribution Feeder Outage Notification) describes how to use CROW to specifically report feeder outages (Which will determine number of customers affected)
How are Power Line Technicians dispatched?
Dispatched through Hydro Restoration Centre (HRC)
How are Station Electricians and CPC Techs dispatched?
- Through the Control Centre
- -SOO 1T-82 describes callout procedures