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Title / Respond to substation secondary systems alarms and indications in the electricity supply industry
Level / 4 / Credits / 4
Purpose / People credited with this unit standard are able to: demonstrate knowledge of control systems associated with an electricity supply substation; describe the functions and components of electricity substation secondary systems; interpret and respond to the operation of substation secondary systems indications and alarms; record and communicate indications and alarms from onsite equipment; and report alarm and response actions.
Classification / Electricity Supply > Electricity Supply - Core Skills
Available grade / Achieved
Explanatory notes
1Safety of personnel and plant must be a priority throughout the assessment.If the safety requirements are not met the assessment must stop and the candidate will be assessed as not yet competent.
2Performance and work practices in relation to the outcomes and evidence requirements must comply with all current legislation, the Electricity Act 1992, regulations, and codes of practice recognised under that statute; Health and Safety at Work Act 2015, the Resource Management Act 1991, electricity supply industry codes of practice and documented enterprise procedures and any subsequent amendments. These include updated versions of the Safety Manual – Electricity Industry (SM-EI) Wellington: Electricity Engineers’ Association. A full list of current legislation and industry codes is available from
3The phrase in accordance with industry requirements is implicit in all outcomes and evidence requirements in this unit standard.
4Definitions
Asset owner refers to the owner of an electricity supply network that takes its point of supply from Transpower NZ or other local reticulation systems, and delivers electricity to industrial, commercial and residential customers.
Industryrequirements include all asset owner requirements; manufacturers’ specifications; and enterprise requirements which cover the documented workplace policies, procedures, specifications, business, and quality management requirements relevant to the workplace in which assessment is carried out.
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of control systems associated with an electricity supply substation.
Evidence requirements
1.1Substation secondary systems are described.
Rangemay include but is not limited to – d.c.system, a.c.system, supervisory control and data acquisition (SCADA), revenue metering, transformer protection, distance protection, bus bar protection, feeder protection, communication system, security system, fire alarm, station control computer, station alarm panel, compressed air system, intertrip systems, water cooling systems.
1.2Control systems components are described.
Rangeincludes but is not limited to – battery charger, battery banks, remote terminal unit, electronic protection relays, mechanical protection relays, a.c.distribution panel, d.c.distribution panel, digital microwave radio.
Outcome 2
Describe the functions and components of electricity substation secondary systems.
Evidence requirements
2.1The functions and components of electricity substation secondary systems are described.
Rangeincludes but is not limited to – d.csystem, a.c.system, SCADA system, revenue metering, transformer protection, distance protection, bus bar protection, feeder protection, station alarms.
2.2The functions and components of electricity substation protection systems are described.
Rangeincludes but is not limited to – transformer, distance, bus bar, feeder, station alarm protection systems.
Outcome 3
Interpret and respond to the operation of substation secondary systems indications and alarms.
Rangeincludes but is not limited to – reason for alarm or indication, acknowledgement and resetting.
Evidence requirements
3.1Transformer protection indications are interpreted and responded to in terms of differential protection, over current protection, earth fault protection, residual voltage, buchholz, tap-change, temperature relay, and winding temperature relay.
Rangeevidence of two different transformer protection indications is required.
3.2Distance protection indications are interpreted and responded to in terms of differential protection, over current protection, earth fault protection, zone 1, zone 2, and zone 3.
Rangeevidence of two different distance protection indications is required.
3.3Bus bar protection indications are interpreted and responded to in terms of differential protection, over current protection, earth fault protection, and circuit breaker fail.
Rangeevidence of two different bus bar protection indications is required.
3.4Feeder protection indications are interpreted and responded to in terms of over current protection and earth fault protection.
Rangeevidence of two different feeder protection indications is required.
3.5Station alarm indications are interpreted and responded to.
Rangetrip circuit defective, circuit breaker warning, circuit breaker defective, circuit breaker operation, protection number 1 defective, signal fail, blocking signal fail, auto reclose operated, circuit protection operated, buchholz (gas), tap changer fault, temperature alarm, earthing resistor temperature, bus bar protection defective, bus bar protection operated, CB fail protection operated, under/over voltage, disturbance recorder, compressor fail, battery charger fail, 110 kV DC earth fault, fire and smoke protection, intruder, metering, communications urgent/ non urgent, vibration;
evidence of four different station alarm indications is required.
Outcome 4
Record and communicate indications and alarms from onsite equipment.
Evidence requirements
4.1Indication sheet recording relay operation is completed.
4.2Indication and interpretations are communicated as required by asset owner.
Outcome 5
Report alarm and response actions.
Rangeincludes but is not limited to – operating log, service report, flagging sheets, quality records, computer based management systems.
Evidence requirements
5.1Recorded information is complete, concise, and legible.
5.2Information is recorded in the required asset owner’s format.
Planned review date / 31 December 2021Status information and last date for assessment for superseded versions
Process / Version / Date / Last Date for AssessmentRegistration / 1 / 22 October 2003 / 1 December 2012
Rollover and Revision / 2 / 20 June 2008 / 1 December 2012
Review / 3 / 21 July 2011 / 31 December 2019
Review / 4 / 16 March 2017 / N/A
Consent and Moderation Requirements (CMR) reference / 0120
This CMR can be accessed at
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA, before they can report credits from assessment against unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and which are assessing against unit standards must engage with the moderation system that applies to those standards.
Requirements for consent to assess and an outline of the moderation system that applies to this standard are outlined in the Consent and Moderation Requirements (CMR). The CMR also includes useful information about special requirements for organisations wishing to develop education and training programmes, such as minimum qualifications for tutors and assessors, and special resource requirements.
Comments on this unit standard
Please contact the Infrastructure ITO (Connexis) if you wish to suggest changes to the content of this unit standard.
Infrastructure ITOSSB Code 101813 / New Zealand Qualifications Authority 2018 / New Zealand Qualifications Authority 2018