HVAC in substation while main power supply loss

[AntonioPerez]

Hi,

I was wondering if there is some standard that considers the situation of an HVAC system for a substation building during a main power supply loss. I'm participating in a project where ventilation was considered to be fed by a backup power supply but no air conditioning is posible while main power loss. Anyway, equipment inside the building has an ambient temperature ratings of 40ºC and heaters inside to prevent condensation. I couldn't find any standard about. What's your opinion?

Thanks in advance.

 

[EnergyProfessional]

If the power comes from the the high-voltage line, you also wouldn't have a cooling load in case of power loss.

If the substation still operates (i.e. your HVAC is served from a different failing source), you need to size the generator to also provide cooling.

It also depends on what duration of power loss you need to cover. Can the equipment be over 40°C for an hour, and you expect power losses less than an hour? Or do you expect days without power?

Not enough information provided to give a good answer. ultimately it is up to the owner/operator what they are willing to spend, and what scenarios they try to avoid.

 

[AntonioPerez]

Thanks EnergyProfessional.
There is an alternative power supply in case of main power loss, but the consumption in this case is substantially reduced at about 7%. The alternative power supply has an autonomy of 8 hours, and often power losses are not expected. Equipment is designed to work at constant 40ºC and I guess that some overtemperature period can be withstanded but I don't know and I don't think that manufacturers can tell so easily.
Anyway, detailed calculations will be done to determine the evolution of temperature, considering possible scenarios but I wanted to know if there is some standard that stablishes some requirement about cooling in case of main power loss. You already answered me, that this is up to the owner, so thanks.