Geared Traction Elevator for Office Buildings: 500–1000 kg, 0.6–1 m/s

1. Is a geared traction elevator the right choice for your building?

A geared traction elevator uses an induction motor with a reduction gearbox to turn the sheave. That one mechanical fact decides almost everything else: where the machine is mounted, how much room it needs, how it sounds, what it costs to run, and what it costs to buy. For a building with a rated load of 500–1000 kg, a travel ceiling of 50 ft and a speed setting of 0.6–1 m/s, the geared arrangement is still an efficient answer, and in some projects it is the cheaper one. In others it is simply the wrong tool.

The three cards below sort your project into one of three states. The middle column is not a rejection: it means the project needs a different drive, a different page, or a site change before this specification can be applied.

A word on travel: 50 ft is shaft travel, not a floor count. Divide it by your own floor-to-floor height. At 2.7 m per floor it covers about five stops, at 3.0 m about five, and at 3.5 m about four. Work this out on the drawing before the drive type is fixed, because the answer changes the specification more often than any other input.

2. How a geared traction drive moves a car

Four components carry the load, and each one has a site consequence you can see before delivery.

• The traction machine turns the sheave. An induction motor runs at a speed that is far too high for a lift car, so a reduction gearbox brings it down to the rope speed that produces 0.6–1 m/s at the car. The trade is simple: the gearbox lets a smaller, cheaper motor move a 500–1000 kg load, and in exchange it adds an oil-lubricated component that needs scheduled attention.
• The sheave carries the load by friction. Ropes pass over the sheave rather than winding onto a drum, so nothing runs out of rope as the car travels and the lift height is not limited by drum capacity. Traction depends on rope tension, groove condition and the load ratio between car and counterweight, which is why rope tension equalisation is part of commissioning.
• The counterweight halves the work. Because the counterweight balances the car plus roughly half the rated load, the motor only has to move the difference. That is what makes a single-phase 220 V supply practical at this load and speed.
• The safety chain stays mechanical. Governing, safety gear and buffers do not depend on the controller being healthy. Keep that separation in mind when you review the drawing: the electrical safety devices on the specification sheet sit on top of a mechanical chain, not instead of it.

Three consequences follow from this arrangement, and all three show up as site requirements rather than as marketing claims. First, the machine has mass, so it needs a structural position that can take it. Second, the gearbox needs oil and access for checking it. Third, the drive is happiest when the load is moderate and the stops are close together, which is precisely the duty an office building with a 50 ft travel ceiling creates.

3. Geared vs gearless for an office building

The geared vs gearless elevator question is usually answered as a technology lecture. On a real office project it is a procurement question with three inputs: how far the lift travels, how often it stops, and how much money is available at the start compared with the running years. The table below compares the two arrangements on those inputs, at the load and speed class this page covers.

If you only keep one line from this section, keep this one: at 50 ft of travel or less with a 500–1000 kg office load, the geared machine is normally the economical specification; the gearless drive earns its higher price when travel grows, speed rises, or the machine cannot be separated from occupied space.

Three decision rules that follow from the table

• Travel decides the drive. Inside 50 ft, the geared machine is inside its comfort zone. Beyond it, look at a gearless drive and a different specification before you look at discounts.
• Duty decides the service plan. Frequent short runs at 500–1000 kg mean more starts per hour, so brake adjustment and rope inspection intervals should be set from the traffic study rather than from a generic calendar.
• The building decides the room. If a machine room can be provided above the shaft, the geared machine needs nothing else. If the room cannot be provided at all, gearless is the answer and the site constraints change with it.

What a 0.6–1 m/s office lift actually does in a working day

Traffic is where an office specification is usually decided, and it is worth doing the arithmetic before the drive type is fixed. On a short run inside 50 ft, a car travelling at 0.6 m/s takes roughly two seconds of travel per floor between adjacent landings, and at 1 m/s closer to 1.2 seconds. Door open and close times, passenger transfer and call answering add far more to a round trip than the travel itself, which is the reason that going faster on a five stop shaft buys almost nothing in waiting time, while a badly set door time costs several seconds on every single trip.

Two conclusions follow for a 500–1000 kg office lift. First, choose the speed from the number of stops and the distance between them, not from the top of the published band. Second, spend the effort on door timing, call allocation and levelling accuracy, because those are what a tenant experiences twenty times a day.

How to compare two geared offers line by line

Offers for the same rated load and travel can differ by several thousand dollars without any of them being dishonest. The differences sit in the items below, so compare them one by one rather than by the headline price.

• The travel actually quoted. One supplier quotes travel, another quotes the number of floors. Convert both to metres or feet before comparing, because a five stop building with a tall ground floor can sit outside the 50 ft ceiling.
• What is inside the car. Handrail, ceiling, lighting, flooring and the car operating panel change the price and the lead time, and they are what the tenant sees every day.
• Doors. Landing door type, finish and clear opening are quoted separately by some suppliers and included by others.
• Control panel and signals. Check which panel, which call arrangement and whether fault memory is readable by the maintenance team.
• The scope split. Confirm in writing who supplies the guide rails, the machine beam, the travel cable, the electrical feed, unloading and installation labour.
• Documents. Approval drawing, test record at handover and the maintenance schedule should be listed in the offer, not promised verbally.

4. Key specifications and unit conversion

These are the values published for the office traction elevator on the product page and its specification sheet. Use them for planning, then confirm the final figures on the approved drawing, because car size, stops and shaft dimensions are fixed per project.

Planning figures you can convert yourself

Two conversions catch people out when they compare offers from different suppliers. Travel is quoted in feet on one sheet and metres on another, and speed is quoted in metres per second on one and feet per minute on the other. The arithmetic is the same in both directions: multiply metres by 3.281 to get feet, and multiply metres per second by 196.85 to get feet per minute.

• 15.2 m travel = 50 ft, which is the ceiling on this specification
• 0.6 m/s = 118 fpm and 1 m/s = 197 fpm, the speed range on this specification
• 500 kg = 1100 lb and 1000 kg = 2200 lb, the rated load range

At a planning assumption of 75 kg per person, the 500 kg end of the range covers about six passengers and the 1000 kg end about thirteen. That is a planning figure only: passenger count, car size and door width are confirmed together on the approved drawing, and the certified load stays the one printed on the plate.

5. Shaft, machine room and site conditions

A geared traction machine needs three things from the building that a hydraulic lift does not ask for: a shaft that runs the full travel, clear space above the top landing for the machine and the car's over-travel, and a pit below the bottom landing. Get those three right on paper and the installation is routine. Get them wrong and the correction costs more than the lift.

The checklist below is the one our engineers use when a contractor sends a pit plan. Tick all three before production drawings are issued.

The other five site items that slow projects down

• Load path. The machine beam transfers the machine load plus the rope tension into the building. Structural steel frames and concrete shafts take this differently, so send the shaft construction type with the pit plan.
• Landing door openings. Confirm clear opening width at every landing, especially if the building moves furniture, medical equipment or cleaning trolleys. Door width also interacts with the car size you can use.
• Access for the machine and the car. A 500–1000 kg machine and the car panels arrive as separate items. Check the route from the delivery point to the shaft head: door widths, turning space and any lifting point above the shaft.
• Machine position environment. The machine position should be dry, ventilated and lockable, with light for maintenance and enough clearance to open the machine for service.
• Outdoor shafts. The specification allows indoor or outdoor installation. An outdoor shaft needs weather protection at the entrances and at the machine position, plus a maintenance interval agreed with the fact that the equipment sees rain and temperature swings.

On a conversion project the same three checks apply, but they are harder to satisfy. Adding a lift to an existing two or three storey office usually means finding shaft space inside the floor plate and accepting a smaller car, or building the shaft against an outside wall where weather protection becomes part of the scope. Both routes work with a geared traction elevator at 500–1000 kg and inside 50 ft of travel, provided the top clearance above the top landing and the pit can be created. Those two dimensions, not the machine itself, are what decide whether a retrofit is straightforward or expensive, so measure them before the layout is drawn.

6. 220 V single-phase power and control

The published supply for this office traction elevator is 220 V, 50 Hz, single phase. On a commercial project that is good news: the electrical contractor does not have to run a three-phase feed to the shaft head, and the supply can usually be taken from the existing distribution without a new transformer.

It also means the specification only holds if the site actually delivers that supply. The card below is the condition check we ask contractors to complete before release to production.

What the microprocessor control actually decides

The specification sheet lists a microprocessor-based control system. Practically, that board is where the day-to-day behaviour of the lift is set: how car and landing calls are registered and answered, how long the doors stay open at each floor, how the car re-levells as passengers step in and out, and what faults are recorded for the service engineer to read.

Three site conditions protect that panel and are worth writing into the electrical scope: keep the machine position dry and ventilated, keep it lockable, and keep the feed free of large switched loads that share the same circuit. None of the three costs much at construction stage and each of them is expensive to correct afterwards.

7. Levelling and ride quality on short runs

At 0.6–1 m/s, passengers never judge the lift by its top speed. They judge it by whether it stops level with the floor, whether it starts and stops without a jolt, and whether the doors behave. On an office lift that makes ten or twenty short trips an hour, those three things are the whole experience.

What is checked at commissioning, and what it depends on

• Levelling at every landing, loaded and empty. Stopping accuracy is checked with the car empty and with rated load, because an office lift changes load quickly during boarding. The acceptance figures come from the standard your project falls under and from the contract, and they are recorded in the commissioning report.
• Start and stop characteristics. Smooth acceleration and deceleration are set in the drive parameters, then verified over the full travel with passengers in the car.
• Door behaviour. Opening and closing time, re-open reaction and interlock function are checked at each landing, because door faults are what occupants actually report.
• Noise at the machine position. The gearbox and machine mounting are checked under running load, particularly if the machine beam shares a wall or slab with occupied space.

Comfort comes from six items, in this order of attention

The list below is the order our service engineers work through when a ride is reported as rough. It is a troubleshooting order, not a scoring system.

1. Guide rail alignment and fixing. Rails that are not straight or not tightly fixed transmit every defect into the car.
2. Rope tension equalisation. Unequal rope tension shows up as vibration that changes with car position.
3. Machine mounting and isolation. Correct pads and a properly seated machine beam decide how much of the gearbox is heard in the building.
4. Brake setting. A brake that releases late or unevenly is felt as a jolt at every stop.
5. Door track and sill alignment. Cheap to correct and the most visible item to occupants.
6. Landing floor finish. A sill set against an uneven floor makes a level car look out of level.

Practical point for contractors: the six items above are the reason to keep the shaft clean and the rails protected until handover. Site damage during fit-out is the most common cause of a rough ride on a machine that was correct when it left the factory.

8. Safety devices and handover checks

Three safety features are published on this specification sheet: emergency stop button, safety sensors and door interlocks. Those are the electrical devices a buyer can point to on the sheet. They sit on top of a mechanical safety chain that is confirmed on the approved drawing, and here is why that distinction matters for the person signing the handover.

Two documents should come out of this section, and both belong in the technical file: the commissioning report with the test results above, and the maintenance schedule with the intervals for brake, rope, guide and gearbox oil checks. The certificates published for this product, CE and ISO, cover manufacture; local approval for the installed lift stays with the buyer's jurisdiction. Contact our engineers.

9. Installation sequence and lead time

The published delivery time is 45 working days, and it starts from order confirmation with the drawings approved. The production clock and the site clock run in parallel, and the project is late only when the second one falls behind schedule. The timeline below shows both tracks.

The single most useful date you can give a supplier is the day the shaft will be ready. On a 45 working day production cycle, a shaft that is three weeks late on a nine-week programme is not a supplier problem, and it is the delay that shows up on the project programme.

Who does what

Scope confusion is the second most common cause of a delayed installation, after a late shaft. The split below is the one we work to; it is confirmed line by line in the offer so that no item is assumed by either side.

Two items in that table decide how smoothly the job runs. The power supply has to be measured at the machine position before the panel is built, and the machine beam has to be ready before the machine arrives. Both are cheap at construction stage and both are disruptive to correct once fit-out is under way.

10. Office traction elevator FAQ

These are the questions that come back from contractors, MEP coordinators and property managers before an order is placed. Each answer states what the published specification supports and where a project figure has to be confirmed on the drawing.

11. What to send for a quotation

An office traction elevator offer is only as good as the inputs behind it. The list below is the full set we need to fix a layout, a price and a delivery date. Send what you have; the items you cannot answer yet are the ones we will ask about, and answering them once is faster than answering them three times.

Commercial terms on this specification

One last point on scope. This page describes an office elevator that is ordered against a drawing: the numbers on the drawing decide the machine, the car, the doors and the electrical supply. If your project sits inside the 500–1000 kg and 50 ft envelope and the shaft head can take the machine, the geared traction arrangement is a dependable specification at this duty. If it sits outside that envelope, say so at enquiry stage and the specification changes with it, in the offer rather than in the building.