Engine Dynamometers (ED Series)

Engine Dynamometer

Product Description

With a Magtrol Engine Dynamometer, high performance motor testing is available to manufacturers and users of small gas engines. Magtrol’s Engine Dynamometers have been designed to address the severe, high vibration conditions inherent in internal combustion engine testing.

Engine Dynamometers are part of Magtrol’s line of Hysteresis Dynamometers so they are highly accurate (± 0.25% of full scale) and can be controlled either manually or via a PC-based Dynamometer Controller. For a small engine test stand, Magtrol offers a full line of controllers, readouts and data acquisition software.

An ED Series Engine Dynamometer is ideally suited for emissions testing as set forth in CARB and EPA Clean Air Regulations. The dynamometers will offer superior performance on the production line, at incoming inspection or in the R&D lab.

As with all Magtrol Hysteresis Dynamometers, engine loading is provided by Magtrol’s Hysteresis Brake which provides: torque independent of speed, including full load at 0 rpm, excellent repeatability; frictionless torque with no wearing parts (other than bearings); and long operating life with low maintenance. Magtrol provides a NIST traceable certificate of calibration, and calibration beam with each engine dynamometer.


  • High-Speed Capabilities
  • Large, Rugged Stainless Steel Shaft
  • Additional Front Shaft Bearing for Greater Support
  • Specially Reinforced Load Cell
  • Gusseted Pillow Blocks
  • Blower Cooled to Maximize Heat Dissipation

Specifications and Drawings

ModelTorque Range
Torque Range
Maximum Speed (rpm)Maximum Power - 5 Minutes (W)Maximum Power - Continuous (W)Downloads
ED-715-5N6.20 N·m55.0 lb·in25,00034003000pdf | step
ED-815-5N28.0 N·m250.0 lb·in12,00070006000step

*NOTE: Operating at the continuous power rating for periods of up to 4 hours is acceptable. However, operating for extended periods at high temperatures will result in premature component and bearing failure. Limiting the length of the cycle and the component temperatures will guard against premature failure. Where continuous duty is desired for longer time intervals, component temperatures should be maintained less than 100°C; monitoring the outside brake surface temperature is a sufficient reference. ** The maximum speed will depend on what type of keyway (if any) is used on the shaft. Unless specified, the dynamometer shaft will be made without a keyway.

  • Model HD-510, HD-515, HD-800 and HD-805 Dynamometers require air cooling provided by user. Regulator and filter package is provided as standard equipment on these units. See data sheet for pressure ratings.
  • Blower package is included as standard equipment with Model HD-710, HD-715, HD-810, HD-815 and HD-825 Dynamometers.
  • All -5N(A) dynamometers are 5 Volt Output

Contact Magtrol for 6N (English), 7N (Metric) and 8N (SI) Specifications

Blower Dimensions

Allow approximately 6 in to 8 in (152 mm to 203 mm) between rear
of dynamometer base plate and blower for connection hardware.
Required hardware is supplied with the dynamometer.

Weight8.5 lb3.9 kg18 lb8.1 kg

Blower Power and Fuses

  • Models HD-710, HD‑715, HD-810 and ED-715 include the BL‑001 blower.
  • Models HD‑815 and ED-815 include the BL‑002 blower.
  • Model HD‑825 uses two BL‑002 blowers for cooling its two brake sets.
BL-001120 V600UL/CSA6.30 A | 250 V | SB
BL-001A240 V500IEC3.15 A | 250 V | T
BL-002120 V1,000UL/CSA15.00 A | 250 V | SB
BL-002A240 V1,000IEC6.30 A | 250 V | T

System Options

To help you select the components for your motor testing system, this table shows which (currently available) electronics and software support Magtrol’s different types of dynamometers.

ModelDescriptionHysteresis Dynamometers (including ED Series)Eddy-current DynamometersPowder Brake DynamometersDial Weight Dynamometers
DSP7000High-Speed Programmable Dynamometer Controller
6200Dynamometer Controller/Readout
TSC 401Torque/Speed Conditioner
5500Dynamometer Switch Box
5501Dynamometer Switch Box
M-TEST 7Motor Testing Software
DES 410/411Power Supply
5241Power AmplifierRequired for HD-825 Only
5200Power Supply
5210Current-Regulated Power Supply
5250Current-Regulated Power Supply
TABDynamometer Tables
AMFAdjustable Motor Fixtures
FMFFixed Motor Fixtures
PTT-Slot Base Plate
FRSFree-Run Speed Sensor
SBB 14Signal Breakout Box

Dynamometer Selection

Magtrol Dynamometers cover a wide range of Torque, Speed and Mechanical Power ratings. To select the appropriate size Dynamometer for your motor testing needs, you will need to determine the Maximum Torque, Speed and Power applied to the Dynamometer:

Maximum Torque

It is important to consider all torque points that are to be tested, not only rated torque, but also Locked Rotor and Breakdown Torque. Dynamometer selection should initially be based on the maximum torque requirement, subject to determining the maximum power requirements.

Maximum Speed

This rating is to be considered independent of torque and power requirements, and is the maximum speed at which the Dynamometer can be safely run under free run or lightly loaded conditions. It is not to be considered as the maximum speed at which full braking torque can be applied.

Maximum Power Ratings

These ratings represent the maximum capability of the Dynamometer Braking System to absorb and dissipate heat generated when applying a braking load to the motor under test. The power absorbed and the heat generated by the Dynamometer is a function of the Torque (T) applied to the motor under test, and the resulting speed (n) of the motor. This is expressed in these power (P) formulas:

SI:P (watts)=T (N·m)xn (rpm)x(1.047 × 10-1)
English:P (watts)=T (lb·in)xn (rpm)x(1.183 × 10-2)
Metric:P (watts)=T (kg·cm)xn (rpm)x(1.027 × 10-2)
All of Magtrol's controllers, readouts and software calculate horsepower
as defined by 1 hp = 550 lb·ft / s. Using this definition:
hp=P (watts)/745.7
To calculate power, use Magtrol's online motor power calculator

The Dynamometer’s ability to dissipate heat is a function of how long a load will be applied. For this reason, the Maximum Power ratings given are based on continuous operation under load, as well as a maximum of 5 minutes under load.

To safely dissipate heat and avoid Dynamometer failure, the maximum power rating
is the most important consideration in selecting a Dynamometer.