When an electric motor fails at a mine site, it is nothing like a breakdown in a city workshop. On a facility set up hours away from the nearest supplier, often in mountainous and demanding terrain, every hour spent waiting for a motor means a stopped conveyor, a starved crusher, an idle crew and lost production. This is exactly why corporate mining operations manage motor procurement not through one-off orders but through long-term supply contracts. As an electric motor manufacturer since 1979, HEM Motor offers the mining sector both products and supply assurance: our contract models built on annual volume commitments, consignment stock, near-site storage and clear lead-time clauses guarantee production continuity at mine sites across Turkiye. In this article we look, from a procurement perspective, at the clauses a mining operation should build its motor supply contract around, how redundancy assurance should be written into the contract, and how remote-site logistics should be planned.

Why the One-Off Order Model Falls Short at a Mine Site

Many operations try to manage their motor needs with a "order as it breaks" approach. For a small facility in a city center this model is manageable; at a mine site, however, it collapses for three core reasons:

  • Distance and access: The distance between the site and the supplier is often hundreds of kilometers. The chain of ordering, approval, dispatch and delivery to the site can take days under a one-off order.
  • Unpredictable demand: Crusher, screen, conveyor and pump motors run under heavy load; a failure gives no warning of when it will arrive. An operation without stock experiences every breakdown as a crisis.
  • Price and budget uncertainty: Making an emergency purchase from the market at every failure leaves the operation at the mercy of that day's stock conditions; the procurement budget becomes impossible to plan.

A long-term supply contract solves all three risks within a single framework: motors are defined in advance, stock assurance is put in writing, dispatch times are committed clause by clause, and the procurement budget becomes predictable on an annual basis.

Industrial electric motors operating on a crusher and conveyor line at a mine site

The Core Building Blocks of a Supply Contract

Annual Volume Commitment and Framework Order

The backbone of the contract is the framework list, in which the motors the operation will purchase over the year are defined by power, speed, frame and mounting type. For a crusher plant, for example, a commitment table might be built around 6 units per year of 15 kW screen motors, 2 units of 75-160 kW crusher motors, and 8 units of the mining sector electric motor range for conveyor drives. The gains this table provides to the operation are as follows:

  • The manufacturer schedules the committed models into its own production plan and creates stock reserved in the operation's name.
  • A volume-based framework provides a clear advantage in unit cost compared with one-off orders.
  • The procurement department is freed from the burden of collecting quotes again at every failure; an order is opened with a single call or e-mail.

When preparing the commitment table, the nameplate data of all motors on site is extracted and the models are standardized. Moving to a three-phase motor standard with common frame and flange dimensions, instead of a scattered fleet collected from different brands, both simplifies the commitment table and allows a single spare to protect more than one point. We covered the matrix logic of how many spares to allocate to each point in detail in our article on the critical spare motor list and stock planning; on the contract side, what matters is that the output of this list is reflected as quantities in the commitment table.

Consignment Stock: Motor on Site, Invoice on Use

The most powerful clause in mining contracts is the consignment stock arrangement. In this model the manufacturer places a certain number of the agreed models on a shelf at the operation's site or at a nearby warehouse; ownership of the motors remains with the manufacturer, and the operation is invoiced only as it draws from the shelf. What the consignment model brings to the mining operation:

  • Zero waiting time: At the moment of failure the motor is already on site; the swap comes down to the maintenance crew's crane and assembly time, without waiting for dispatch.
  • Capital not tied up: The operation does not pay for the motors on the shelf until it uses them; working capital is not buried in stock.
  • Automatic replenishment: Every motor drawn from the shelf is replaced by the manufacturer with a new one within the lead time defined in the contract; the shelf level never drops.

There are two details to watch in the consignment clause. The first is the counting and reconciliation period: shelf movements should be mutually confirmed through a joint count, monthly or quarterly. The second is storage conditions: the responsibility for keeping motors in a dry, vibration-free environment and for periodically rotating the bearing position on long-standing units should be defined in the contract.

Near-Site Warehouse and Regional Stock Point

Not every mine site is of a scale to set up a consignment shelf. In that case the intermediate solution is for the manufacturer to hold reserved stock in the operation's name at a regional stock point. Written into the contract as "2 units of model X and 1 unit of model Y are kept reserved in the operation's name at all times," this clause reduces the motor's delivery time to the site from a dispatch out of the production center to a dispatch out of the regional warehouse. Working with a manufacturer that has a strong stock infrastructure across Turkiye is the precondition for this clause not remaining mere words on paper.

Remote-Site Logistics: Operational Details to Write Into the Contract

Sending a motor to a mine site is not the same as handing a parcel to a courier. A cast iron motor above 90 kW starts at a few hundred kilograms and reaches weights exceeding a ton; stabilized roads, ramps and on-site crane operations are a natural part of the job. In a well-written contract the logistics section covers the following headings:

  • Delivery point definition: Is delivery ex works, at a transfer warehouse in the provincial center, or at the site store? Each option means a different responsibility and insurance limit; it must be defined unambiguously in the contract.
  • Packaging and transport standard: On long, jolting journeys, shaft-end protection, pallet fixing and a moisture barrier are critically important. A motor that reaches the site with bearing damage is more costly than a motor that never arrived.
  • Lifting and unloading responsibility: On the site side, confirmation that forklift or crane capacity matches the heaviest motor to be delivered should be tied to a pre-dispatch checklist.
  • Emergency dispatch protocol: A fast-tracked dispatch channel (dedicated vehicle, weekend dispatch) to come into play for unplanned stoppages instead of the standard lead time, and the conditions for operating this channel, should be written as a separate clause.

Cast iron body asynchronous motors being prepared for dispatch and a consignment stock shelf

SLA and Lead-Time Clauses: Assurance in Writing

What sets a supply contract apart from an ordinary price agreement is the service level commitments (SLA). The core SLA items a mining operation should bring to the table are:

  • Dispatch-from-stock time: The maximum time from order approval to dispatch for standard models on the framework list. With a manufacturer that works from stock, this time can be committed within a band from same day to a few business days.
  • Supply-from-production time: A separate and realistic lead-time definition for motors with special windings, special shafts or adaptation to site conditions.
  • Consignment replenishment time: The maximum number of days within which a motor drawn from the shelf will be replaced.
  • Technical response time: The maximum time within which the manufacturer will respond to requests such as nameplate matching, frame-size confirmation or a commissioning question.
  • Delay penalty and remedy mechanism: The remedy that comes into play when an SLA is exceeded (priority production slot, free fast-tracked dispatch and the like) must be clear. The aim is not to impose penalties but to mutually secure the seriousness of the commitment.

For the SLA clauses to be realistic, the counterparty must genuinely be a manufacturer. When import and intermediary layers come between, no seller can give a strong lead-time commitment for a supply chain not under its control. As a brand that produces motors in its own facility and holds stock in Turkiye, HEM Motor stands behind its SLA clauses with production capacity.

Which Motors Should Be Within the Contract Scope?

The motor fleet at a mine site generally consists of three layers, and the contract should address each layer with a different level of assurance:

  • Those that directly stop production: Primary and secondary crusher drives, main conveyor motors, screen drives. For this layer our stone crushing and screening plant motors range is configured with a cast iron body and a heavy-duty bearing arrangement; consignment or site stock is mandatory in this layer. You can find the subtleties of power and speed selection in crusher drives in our article on crusher plant electric motor selection.
  • Those that slow production down: Dewatering pumps, dust suppression systems, auxiliary conveyors. Regional reserved stock is generally sufficient.
  • Those that affect comfort: Workshop and facility auxiliary equipment. Since they are standard asynchronous motor models, they can be supplied with normal lead time through the framework price list.

This layering also balances the cost of the contract: taking consignment assurance for every motor is needlessly expensive; securing the critical layer and managing the rest with framework lead time is the most efficient arrangement. Being able to manage the entire range from 0.55 kW auxiliary drives to 355 kW crusher motors from a single manufacturer, with a single contract, provides a serious simplification on the procurement side.

The Difference of a Direct Contract With the Manufacturer

The first question to ask when choosing the party with which to sign a supply contract is this: does the firm in front of me produce the motor, or is it waiting for it to arrive from abroad? At HEM Motor, which has produced industrial electric motors since 1979, the structure we offer our contract customers rests on these elements:

  • Production and stock depth from 0.55 kW to 355 kW in the IE3 and IE4 efficiency classes,
  • Cast iron body, reinforced bearings and IP55 protection standard according to mining conditions,
  • The flexibility to set up the full range of consignment, reserved stock and framework order models,
  • Exact matching of motors left over from old brands via the nameplate, and their inclusion in the contract list,
  • A fixed point of contact throughout the contract term: the same sales engineer, the same technical team.

A relationship built directly with the manufacturer also produces value in the later years of the contract: field feedback is reflected into the product, motor configuration is revised for recurring failure points, and the commitment table is updated each year according to actual consumption.

Preparing for the Contract Negotiation: A Checklist for the Procurement Team

The way to sit down strong at the table runs through knowing the site by the numbers. Before entering a supply contract negotiation, the file the procurement and maintenance teams should prepare together consists of these headings:

  • Motor inventory: A breakdown of all motors on site with nameplate photos, including power, speed, frame size, mounting type (B3, B5, B35) and protection class. The inventory is the raw material of the framework list.
  • Failure history: Motor replacement records for the last two or three years. The answer to the question of how many motors each point consumes per year turns commitment quantities from guesswork into data.
  • Downtime cost calculation: The cost to the operation of one hour of downtime on the main crusher or main conveyor. This figure makes the budget justification for assurance clauses such as consignment stock defensible before management.
  • Growth plan: If there is a new line, capacity increase or quarry expansion coming into service in the upcoming contract period, its motor needs should be written into the framework now.
  • Current contract and warranty status: Warranty coverage still running and the end dates of any old supply agreements; the transition plan is built accordingly.

Once this file is ready, the negotiation proceeds over concrete quantities, concrete lead times and concrete assurance levels instead of general promises. Our experience is this: an operation that knows its inventory always extracts more value from the contract.

Budgeting and Seasonality: The Financial Side of the Contract

Motor consumption in mining shows seasonality; failure frequency rises in the intensive production season, while planned changes come to the fore in winter maintenance periods. A good supply contract meets this cycle on the financial side too. The framework agreement should fix the total annual volume while leaving the draw-down schedule flexible: the operation draws quickly from the shelf in the busy season and schedules planned replacements in the quiet period. On the payment side, the consignment model already brings a pay-as-you-use basis, aligning cash flow with the production tempo. In planned replacement items, replacing old and inefficient motors with IE3 and IE4 class models becomes an item that finances itself within the contract period at mining operations where the energy bill is high. Adding an annual planned replacement quota to the contract is the cleanest way to advance this transition gradually without turning it into a budget surprise.

The contract term is also part of the financial design. A common starting model is one plus one years: in the first year you see how well the commitment table overlaps with actual consumption, and in the second year you continue with updated quantities. For operations with a long site life and a settled production plan, a three-year framework fixes both the stock assurance and the commercial conditions more strongly. Whichever term is chosen, an annual review meeting and a quantity revision mechanism must be written explicitly into the contract; otherwise the framework list drifts away from the reality of the site in its second year.

Frequently Asked Questions

Is there a minimum annual quantity requirement for a supply contract?

There is no rigid lower limit; what is decisive is the criticality of the motor fleet and the model variety. Even a site that consumes a few large-power motors per year can build a meaningful contract with a reserved-stock clause on critical models. The right arrangement is determined together after the site inventory is extracted.

Who is responsible for the maintenance of motors in consignment stock?

It is defined in the contract; in common practice, the suitability of the storage environment is the operation's responsibility, while providing the instructions for periodic shaft rotation and visual inspection on long-standing motors is the manufacturer's responsibility. In HEM Motor consignment setups, the shelf layout and storage instructions are provided together with delivery.

What happens if the models change during the contract?

The framework list is a living document. When the site sets up a new line or replaces an existing motor with a more efficient model, the commitment table is updated with a supplementary protocol. The annual review meeting is the natural ground for this update.

Get a Quote

If you want to turn redundancy and stock assurance for your mine site into a written commitment, contact us with your motor fleet inventory and let us build a supply contract model tailored to you together. You can reach our sales engineers at +90 (532) 345 49 86 or through our contact us page. HEM Motor: producing since 1979, standing by your site with its stock as your solution partner.