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Electric Motors/Help calculating standing desk motor inrush for surge protection


QUESTION: Hello, I recently purchased a sit/stand desk and need help determining if the power supply can be plugged into a surge protection strip along with other equipment (imac, external monitors, etc) or needs its own dedicated surge-protected outlet. I'd like to protect this sizeable investment and prevent any damage to neighboring components and circuit breakers.

The figure I am having trouble calculating is the motor and controller's total max load with inrush.
The manufacturer's "help desk" is helpless.

Here are the specs taken from nameplates and this page

Travel speed   1.5''/second (varies - slowest with maximum load) with soft start/stop actuator motors
Weight capacity   355 lbs
Voltage   Input: 110 V
Output: 31 V
Transformer power   200 W (0.2 W on standby)
Power supply current   5 amps

Model: JCB35N2-110
Input: 120V~60Hz, Max.270W
Output: DC 24V 4A/Linear Actuator
Duty Cycle: 10%, Max.2 min operate/Min. 18 min stop

Linear Actuator--
Model: JS36DR-3-R-650/560
Input: DC24V 4A
Max. Load: 800N
Duty Cycle: 10%, Max.2 min operate/Min. 18 min stop

Thanks in advance.

ANSWER: Here is a link to very good article.

In your case the Voltage surge protection will be at the 120Volt plug in.
Surge protection is not current based so it doesnt matter what the current draw is.
Voltage surge protection is protect the equipment from any voltage surges in excess of 120V.

The atricle describes this very well.
Hope this helps

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QUESTION: That's funny, I just spoke with Tripplite tech support a few days ago about this and they mentioned they could not recommend anything without knowing motor and controller's total max load with inrush. Can you help?

Some power bars have a 15 amp or 10 amp capacity as a total current draw distributed over 4 or 5 plugs with different loads. So there may be current protection built in as well, which would trip should the current go past the maximum.

If you are looking to protect the desk motor from overloading and burning out, install a fuse on the 24 V supply to the actuator supply at 4x1.1=4.4 amps DC. This is based at 10% overload OR you can limit it at 5% overload so 4.2 Amps DC
The fuse will blow if the motor ever overloads and will protect it from burning out.
have a close look there must already be some overcurrent protection in place.

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Harcharan Singh Diocee


Electric motor winding redesign, AC and DC. Troubleshooting, motors controls generators. Vibration analysis, dynamic balancing, root cause analysis: electrical and mechanical.


thirty five years electro-mechanical and Senior Management


Journeyman Motor Rewinder, Millwright, Industrial Electrician, Vibration Analyst level II. Certified Electrical Technician ASTTBC, FSR Class B, in BC. Laser alignment specialist. Marine machinery repairs. Business Management Certificate. Last 19 yrs as Plant Manager

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