A backup generator arrives at Fisher Plaza.

More maintenance work is planned Saturday night at Fisher Plaza East, which was hit by a fire and electrical outage earlier this month. Adhost Internet LLC, one of the colocation providers at Fisher Plaza, writes in a blog post that the eight-hour window is the second phase of a three-part process of "restoring normal power" to the internet hub.

Given the heat wave hitting Seattle right now, cooling is likely to be a major concern for data center tenants. Michael Smith, chief technical officer at Adhost, blogs that "there will be periods during which Adhost’s East data center cooling infrastructure is running in a degraded mode" but says there are procedures in place to ensure "the data center temperature will remain well within tolerances throughout the maintenance window."

Smith writes that Adhost doesn't anticipate any loss of service during the maintenance but invites tenants to be present, just as he did during previous round of work last weekend.

Here's an excerpt from Smith's post:

This maintenance window is Phase 2 of 3 in the process of restoring normal power to Fisher Plaza East, delivered from Seattle City Light and backed up by generators within the facility. During this phase, Fisher engineers will install a temporary connection to Seattle City Light. This means Adhost’s East data center will be receiving power from the City with redundant backup generators outside of the building until Phase 3 is completed and permanent power is restored to the facility.

During this event, there will be periods during which Adhost’s East data center cooling infrastructure is running in a degraded mode. Specifically, Adhost has 4 separate Computer Room Air Conditioning (CRAC) units in our East facility. Two have power fed from one riser and two are fed from a different riser. During the maintenance window, power will be interrupted several times to each of the risers that feed the CRAC units for approximately 30 minutes each.

The Method of Procedure for this event requires that a cool down period be observed between each of the riser outages. So, Adhost’s East facility will be pre-cooled to 65 degrees before the event and then re-cooled to 65 degrees between each riser outage. This ensures that the data center temperature will remain well within tolerances throughout the maintenance window.

We do not anticipate any loss of service during the window. However, if you would like to be here during the event, please arrive at Fisher Plaza no later than 9:00 PM on 08/01. During the maintenance window access to the building will be restricted, so anyone arriving after 9:00 PM may not be granted access into the facility until the end of the maintenance window.

Adhost’s Plaza West facility will not be affected by this event, as it has been unaffected throughout the recent power issues localized to the Fisher Plaza East building.

The Fisher Plaza fire in early July knocked several major websites offline, including Bing Travel and Authorize.net.

See previous coverage:
How the Seattle data center fire caught companies unprepared
Photos: Inside the Fisher fire
Swedish Medical Center mulls data stragey after Fisher fire

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