Power Supplies at Altitude: What Buyers Should Put in the RFQ

Specify the installation site, not just the destination country

A distributor buying one power supply for several equipment installations needs more than a destination country on the quotation. Ask where the equipment will operate, including the highest intended installation altitude. Keep an unknown site requirement open rather than assuming that a sample approved at one location covers every location in the rollout.

This matters for buyers supplying customers across the United States, Canada and other international markets. A shipping address identifies the delivery point; it may not identify the operating site. Ask the project owner to provide the installation envelope before selecting a common supply.

Request separate operating and safety confirmation

TDK-Lambda identifies thermal management, power derating and insulation-spacing considerations among the issues relevant to power supplies operating at altitude. These are separate review topics. A supplier response about available output power does not, by itself, answer whether the proposed configuration is suitable for the installation altitude.

Request the model-specific operating limit and the supporting installation or safety documentation. Have the responsible engineer review both. This article does not establish an altitude rating for any Voltivo Power product or prescribe a universal clearance or derating factor.

Send a site envelope that suppliers can answer

Operating altitude

State the maximum intended altitude above sea level and the units. Distinguish powered operation from unpowered shipping or storage.

Temperature and installation

Describe the expected ambient conditions, enclosure, mounting arrangement and available cooling. Identify requirements that still need engineering confirmation.

Electrical demand

Provide the input range, output voltage, continuous load and any peak-load sequence for each equipment variant.

Proposed configuration

Identify the supply model, output option, accessories and installation instructions to which the supplier response applies.

Required evidence

Ask for document titles, revisions and applicable conditions, plus a list of requested conditions that are not yet covered.

Ask suppliers to answer each item explicitly. If the operating sites are not yet known, request the limits of the proposed configuration so the project team can decide whether it fits the planned rollout.

Compare usable output under the same conditions

Do not compare only the largest wattage in each quotation. Ask how much output is available under your combined installation conditions, and which instructions or curves support the answer. TDK-Lambda explains that input voltage, temperature and cooling can affect allowable output. The applicable restrictions must come from the proposed model documentation, not a percentage copied from an unrelated product.

For example, imagine a distributor supplying the same terminal to several indoor sites with different elevations. This is a planning example, not a customer case. The buyer can send a site matrix and ask each supplier to mark every row as supported, requiring evaluation, or outside the proposed configuration. If one site needs another supply or installation arrangement, make that exception visible in the quote comparison.

Do not accept an unspecified promise of suitability for the entire country as a substitute for the site matrix. Likewise, do not treat a general product-family statement as evidence for an unlisted model or output variant.

Close the evidence gap before a repeat order

Record the accepted installation envelope alongside the approved model and document revisions. If further evaluation is needed, have the equipment engineer define the conditions and acceptance criteria before ordering evaluation samples. A successful demonstration should identify the configuration and conditions actually evaluated.

For distributors, pass the accepted installation limits to the team selecting supplies for downstream projects. Reopen the review if a new site exceeds the agreed envelope or an equipment revision changes the load or cooling. A repeat part number is useful only when its documented conditions still match the application.

When contacting Voltivo Power, include the intended operating altitude, input and output requirements, installation conditions, destination markets and expected quantity. We can review the sourcing request against proposed product documentation; suitability and available evidence need confirmation for the specific configuration.