Specifying and comparing quotations for electrical equipment

Why quotations for the same equipment differ

Two quotations for a 250 kVA stabilizer or a 1,000 kVA transformer can describe quite different things. One may include protections, testing, documents, delivery to site and commissioning; another may include only the equipment at the factory gate. The difference in price often reflects a difference in scope rather than in the equipment itself. A meaningful comparison starts by making the scope the same.

Start with a specification

The most effective way to receive comparable quotations is to send the same specification to every supplier. A useful specification for electrical equipment states:

• The duty: load, supply conditions and operating pattern, rather than only a rating
• Performance requirements: the values that matter to the application, each with the condition under which it applies
• Construction and installation: indoor or outdoor, enclosure, cooling, mounting and terminations
• Protection and interfaces: what the equipment must protect, and which signals it exchanges with other systems
• Verification: the inspections and tests required, and whether any are witnessed
• Documents: drawings for approval, manuals and records at handover
• Commercial scope: delivery point, installation, commissioning, training and warranty terms requested

The selection guides and buyer checklists list the technical inputs for each product family.

Ask suppliers to state their departures

Ask each supplier to list any clause they do not meet, with what they offer instead. A quotation without stated departures is not necessarily compliant; it may simply not have been checked against the specification. A clear list of departures makes the offers easier to compare and avoids discovering differences after order.

Align scope before comparing price

When quotations arrive, compare them clause by clause before comparing totals. The elements that most often differ are:

• Rating basis: kVA at what input range, ambient temperature and duty
• Included protections and options: listed explicitly, not implied by a class name
• Testing: which tests, by what method, and which records are supplied
• Documents: what is supplied before manufacture, at dispatch and at handover
• Delivery point: ex-works, delivered to site, or unloaded and positioned
• Installation and commissioning: included, optional or excluded, and who provides cables, foundations and terminations
• Warranty: terms, start date and conditions, as stated in each quotation
• Validity and exclusions: what the price excludes and how long it is valid

Where one quotation omits an item that another includes, ask for it to be priced or confirmed as excluded, so that the totals compare the same scope.

Lifecycle considerations

The purchase price is one part of the cost of owning equipment. Losses over the working life, maintenance needs, access to spares and the availability of records for service all affect the total. For transformers, losses are often stated in the specification so that they can be considered with price. For other equipment, ask how the offer addresses maintenance and service over the equipment's life.

Clarify before ordering

Questions raised during comparison should be answered in writing and reflected in the final quotation or order. Verbal assurances that do not appear in the order documents are hard to rely on later.

Invitrona quotations

An Invitrona quotation states the requirement basis, the proposed configuration, assumptions, departures, inclusions, exclusions and responsibilities. Warranty terms are stated in the quotation. To request one, describe your requirement in the enquiry form and note that a specification is available; it is requested when the review begins. See also what a complete technical submission contains.