ACPM 900
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Built for the elevator systems that carry the biggest responsibility

The Imperial Electric 908-OB Gearless AC Machine is designed for elevator systems that demand exceptional performance, reliability, and capacity. Built for both modernization and new construction projects, it combines advanced AC permanent magnet technology with a robust double-wrap traction design to support high-speed and heavy-load applications.

Whether serving a busy office tower, healthcare facility, mixed-use development, or high-rise residential building, the 908-OB delivers the smooth operation and dependable performance today's buildings require.

Built to handle bigger demands

As buildings become taller and passenger traffic increases, elevator systems need equipment that can move more people, more efficiently.

The 908-OB supports:

High-speed performance

Up to 2,000 fpm for 1:1 roped applications.

High-capacity operation

Up to 16,000 lb car capacity for 2:1 roped applications.

Heavy-duty load handling

Up to 120,000 lb sheave shaft load and 60,000 lb suspended load.

Precision that passengers notice

The best elevator rides are often the ones passengers never think about.

The 908-OB is engineered to deliver:

Smooth acceleration and ecdeleration

Provides consistent ride comfort throughout the journey.

Quiet operation

Helps create a more comfortable environment for building occupants.

Accurate speed control

Maintains precise elevator performance across a wide range of operating conditions.

Designed for efficiency

The 908-OB utilizes AC permanent magnet technology to help reduce energy consumption while maintaining outstanding performance.

Highly efficient operation

Helps support building energy goals.

Cooler running performance

Designed to operate efficiently under demanding conditions.

Oil-free design

No oil lubricants required, helping reduce maintenance and environmental impact.

Engineered with safety in mind

Safety is built into every aspect of the 908-OB.

Dual independent brakes

Provides enhanced stopping performance and operational confidence.

Four-calliper braking system

Includes two primary brake calipers and two emergency brake calipers.

125% rated capacity holding power

Designed to support demanding elevator applications without the need for an external rope brake.

Flexible pplication support

The 908-OB is designed to fit a variety of project requirements.

Modernization projects

A practical replacement solution for existing gearless systems.

New construction

Supports both 1:1 and 2:1 roped installations.

Multiple installation configurations

Suitable for overhead, basement, and side-pull applications.

Why choose the Imperial Electric 908-OB?

The 908-OB brings together the performance of a high-capacity machine with the efficiency and precision of modern gearless AC technology.

For elevator professionals, consultants, and building owners seeking a proven solution for high-rise and heavy-load applications, it delivers the reliability, ride quality, and operational confidence needed to keep people moving.

Explore the 908-OB

View product specifications

Review detailed technical capabilities and application information.

Download the datasheet

Access performance data, dimensions, and configuration details.

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Need help selecting the right solution for your project? Contact our customer service team for expert guidance and support.

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  • MODEL 908 OB-E
    • 4,500 lbs capacity Up to 1,400 fpm 1:1 Roping
    • 9,000 lbs capacity Up to 700 fpm 2:1 Roping
    • Double wrap
    • 30.0” drive sheave
    • Rope Groove hardness: 245-285 Brinell
    • Up to Qty 9-5/8 or 7-3/4” ropes Double Wrap
    • Round U Groove
    • D:d ratio 48:1 with 5/8” ropes
    • D:d ratio 40:1 with 3/4” ropes
    • Sheave shaft Load: 120,000 lbs
    • Quad Independent disk brake system holds 125% rated capacity-2 each
    • Overhead, Basement & Side pull Application
    • Extra mounting restraints are needed for Basement & Side pull Application
    • M/C Weight: 14,200 lbs
    • M/C Torque:
    • Rated Torque 908 OB 4853 ft-lb, Accel Torque: 12132 ft-lb
  • Model 908 OB-H
    • 8,000 lbs capacity Up to 2,000 fpm 1:1 Roping
    • 10,000 lbs capacity Up to 1,000 fpm 1:1 Roping (Special Applications)
    • 16,000 lbs capacity Up to 1,000 fpm 2:1 Roping
    • Double wrap
    • 30.0” drive sheave
    • Rope Groove hardness: 245-285 Brinell
    • Up to Qty 9-5/8 or 7-3/4” ropes Double Wrap
    • Round U Groove
    • D:d ratio 48:1 with 5/8” ropes
    • D:d ratio 40:1 with 3/4” ropes
    • Sheave shaft Load: 120,000 lbs
    • Two Independent Hydraulic disk brake system holds 125% rated capacity - 2 each
    • Overhead, Basement & Side pull Application
    • Extra mounting restraints are needed for Basement & Side pull Application
    • M/C Weight: 15,200 lbs
    • M/C Torque:
    • Rated Torque 908 OB – 6490 ft-lb, Accel Torque: 16225 ft-lb

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Notice

Frame 908-OB E Series 1:1 Duty Table 

FPM 500 700 800

1000

 1200 1400 1600 1800 2000
Freq. (Hz) 17 23.8 27.2 34 40.7 47.5 542.3 61.1 67.9
RPM 63.7 89.1 102 127.3 152.8 178.3 203.7 229.2 254.6
Capacity HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps
2000 16.8 37 23.6 37 26.9 37 33.7 44 40.4 53 47.1 64 53.9 67 60.6 83 67.3 83
2500 21 46 29.5 46 33.7 46 42.1 55 50.5 66 58.9 80 67.3 84 75.8 104 84.2 104
3000 25.3 56 35.4 56 40.4 56 50.5 67 60.6 79 70.7 97 80.8 101 90.9 124 101.0 124
3500 29.5 65 41.2 65 47.1 65 58.9 78 70.7 93 82.5 113 94.3 118 106.1 145 117.8 145
4000 33.7 74 47.1 74 53.9 74 67.3 89 80.8 106 94.3 129 107.7 134 121.2 166 134.7 166
4500 37.9 84 53 84 60.6 84 75.8 100 90.9 119 106.1 145 121.2 151 136.4 187 151.5 187
Model 908-OB E All specifications at 50% Counterweight. Consult Imperial Electric for
40% and 45% counterweighting data.

 

Frame 908-OB H Series 1:1 Duty Table 

FPM 500 700 800 1000 1200 1400 1600 1800 2000
Freq. (Hz) 17 23.8 27.2 34 40.7 47.5 542.3 61.1 67.9
RPM 63.7 89.1 102 127.3 152.8 178.3 203.7 229.2 254.6
Cap. HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps
5000 42.1 93 58.9 93 67.3 93 84.2 111 101.0 132 117.8 161 134.7 168 151.5 207 168.4 207
5500 46.3 102 64.8 102 74.1 102 92.6 122 111.1 146 129.6 177 48.1 185 166.7 228 185.2 228
6000 50.5 112 70.7 112 80.8 112 101.0 133 121.2 159 141.4 193 161.6 202 181.8 249 202.0 249
6500 54.7 121 76.6 121 87.5 121 109.4 144 131.3 172 153.2 209 175.1 218 197.0 270 219.9 270
7000 58.9 130 82.5 130 94.3 130 117.8 155 141.4 185 165.0 225 188.6 235 212.1 290 235.7 290
7500 63.1 139 88.4 139 101.0 139 126.3 166 151.5 198 176.8 241 202.0 252 227.3 311 252.5 311
8000 67.3 149 94.3 149 107.7 149 134.7 177 161.6 212 188.6 257 215.5 269 242.4 332 269.4 332
Model 908-OB H All specifications at 50% Counterweight. Consult Imperial Electric for
40% and 45% counterweighting data.

 

Frame 908-OB E Series 2:1 Duty Table 

FPM 350 400 450

500

 700 800 1000
Freq. (Hz) 23.8 27.2 30.6 34 47.5 54.3 67.9
RPM 89.1 102 114.6 127.3 178.3 203.7 254.6
Capacity HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps
3000 18.7 30 21.4 30 24.1 35 26.7 35 37.4 51 52.8 53 53.5 66
4000 25.0 39 28.5 39 32.1 47 35.7 47 49.9 68 57.0 71 71.3 88
5000 31.2 49 35.7 49 40.1 59 44.6 59 62.4 84 71.3 89 89.1 110
6000 37.4 59 42.8 59 48.1 70 53.5 70 74.9 102 85.6 107 107.0 132
7000 43.7 69 49.9 69 56.1 82 62.4 82 873 119 99.8 125 124.8 154
8000 49.9 79 57 79 64.2 94 71.3 94 99.8 136 114.1 142 142.6 176
9000 56.1 89 64.2 89 72.2 106 80.2 106 112.3 153 128.3 160 160.4 198
Model 908-OB E All specifications at 50% Counterweight. Consult Imperial Electric for40% and 45% counterweighting data.

 

Frame 908-OB H Series 2:1 Duty Table 

 
FPM 350 400 450

500

 700 800 1000
Freq. (Hz) 23.8 27.2 30.6 34 47.5 54.3 67.9
RPM 89.1 102 114.6 127.3 178.3 203.7 254.6
Capacity HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps HP Amps
10000 62.4 98 71.3 98 80.2 117 89.1 117 124.8 170 142.6 178 178.3 220
11000 68.6 108 74.4 108 88.2 129 98.0 129 137.3 187 156.9 196 196.1 242
12000 74.9 118 85.6 118 96.3 141 107.0 141 149.7 204 171.1 214 219.9 264
14000 87.3 138 99.8 138 112.3 164 124.8 164 174.7 239 119.6 249 249.6 307
15000 93.6 148 107.0 148 120.3 176 113.7 176 187.2 256 213.9 267 267.4 329
16000 99.8 158 114.1 158 128.3 188 142.6 188 199.6 273 228.2 285 285.2 351
Model 908-OB E All specifications at 50% Counterweight. Consult Imperial Electric for40% and 45% counterweighting data.