Some angry residents are facing a day working from home without power as Vector carries out preplanned maintenance work.

Mt Roskill resident Michael Todd received a letter from Vector today saying power would be cut for 10 hours next Tuesday while pole replacement work is carried out as part of improvements to the local power supply.

Vehicle access to parts of Gilletta Rd would also be restricted as trucks and maintenance vehicles need the space.

Todd said it was ridiculous to carry out work like this while people are in enforced self-isolation to try and slow the spread of coronavirus which has already affected 155 people.

Many people trying to work from home and have school children who are meant to be learning online.

"This work should be delayed or staggered as the entire street will be at home locked inside together with no power. In our house alone there will be 7 people, all adults working from home. I assume all other houses will be similar.

"Worse is that my partner and I are both accountants and 31 March is an important date, but that aside, with no ability to cook or have heating or even make a coffee, this is ridiculous!!

"This is a stupid time to do this."

Todd said unless it was urgent any preplanned work should be done in two-to-three-hour blocks, "not an entire 10-hour workday".

• Covid19.govt.nz: The Government's official Covid-19 advisory website

And the frustrated Gilletta Rd resident isn't the only one facing a day juggling children and work without power.

A Muriwai woman, who only gave her first name Teresa, said she received an email about a planned cut between 8am and 5pm on Thursday.

"(I'm) meant to be running business from home and kids online home learning … (it's) hopeless – they should delay this."

In a letter to Gilletta Rd residents Vector said the planned work, which had earlier been communicated, was being done to "safely complete some pole replacement work".

There would be a limited number of reserved carparks further down the street and traffic control marshalls would be available to help if needed.

"We thank you for your patience while we complete this work and apologise for any inconvenience it may cause".

A Vector spokesman said the company was very aware that families and communities were going to be based at home and even more reliant on the continuity of power.

"Like everyone, Vector is dealing with a rapidly changing situation. Vector has been assessing all planned works for the upcoming four weeks. We are in the process of postponing or cancelling all non-essential planned work."

The spokesman said there was however some essential work that needs to continue. He wasn't able to comment on whether that work included the planned outage in Mt Roskill or Muriwai.

"We know these are difficult and stressful times for people being at home more and we will do our very best to minimise outage impact on customers. Our people are doing their very best for all our customers and thank the customers for their understanding."

From Thursday New Zealanders will be in a nationwide lockdown. That means all schools, universities and non-essential services - including bars, restaurants, cinemas, museums, gyms and libraries - will be closed.

Everyone who is not in an essential job will be required to self isolate for at least the next four weeks.

Forty new cases of the virus were confirmed today, bringing the number of people infected - or highly likely to be infected - to 155. Twelve of those people have already recovered and six are in hospital.

Four of the case are deemed to have been from community transmission, one of the major reasons why the country is about to be fully locked down. It is hoped self-isolation will slow the spread of community transmission.