Writing an Equipment Spec for a Voice Alarm System: What to Put in Your Procurement Requirements

A well-drafted specification for a PA/VA (public address and voice alarm) system spares you the pain of re-approvals and slipped delivery dates. In Russian procurement practice this document is called a TZ — a set of technical requirements handed to the supplier. Below is a practical checklist of what to put into the equipment spec so your supplier can assemble and quote the correct package on the very first request.

How does an equipment procurement spec differ from a full system design?

The specification sets out the requirements for the equipment — its make-up and ratings: power, the number of zones, loudspeaker types, line standards, and documentation. The full design — device layout, acoustic calculations, and working documentation — is produced by a licensed engineering firm. VPA supplies the equipment by invoice and helps you put together an accurate specification based on your site's input data.

How much amplifier power headroom should the spec call for?

Typically 20–30% on top of the combined power of all the loudspeakers. That headroom offsets line losses, equipment ageing, and any future expansion of the system. Sizing the amplifier with no margin invites overload and distortion in an emergency — exactly when the system has to perform.

Should the spec name specific loudspeaker models?

It is enough to state the type (ceiling, wall-mount, horn, or column loudspeakers) and the quantity per zone, together with the requirement for 70/100V line operation and the target speech intelligibility. The supplier will pick specific models to suit the room acoustics and back the choice with calculations.

How should the spec account for interfacing with a regional warning network?

If the site ties into Russia's civil-defence emergency framework (GOChS / RASTSO, the regional centralized public warning system), the specification should include a P-166Ts BUU-02 interface unit and call out a priority input for external signals. The exact interfacing requirements are set by a licensed firm at the design stage.

What should the spec require for outdoor zones?

An all-weather build with dust and moisture protection and an operating temperature range matched to the site's climate, plus extra output to ride over the ambient noise. For open areas, the usual choice is horn loudspeakers in a weatherproof enclosure.

Which equipment documents should you request from the supplier?

Proof of conformity with EAEU (Eurasian Economic Union) requirements, the warranty terms and the stated service life, and information on stock availability and lead times. VPA equipment is certified to EAEU requirements, ships with a 24-month warranty, and carries a rated service life of at least 10 years.