Video AC Motor interference

[The JC]

Hi folks,

I’ve got 4 LITE-D 591.TM01 3phase winch motors in use. They are located substage, with control hub backstage, directly above motors (Circa 3m separation between the two levels) Have a BlackMagic dual monitor screen set up next to the control hub to spot the stage while using winches. Whenever winches are operated, the video relay flickers intermittently. We have multiple feeds of the video dotted around the venue and it’s only the screens by the control hub which flicker. Winches are on their own 3phase supply separate from the circuits the dual monitor screen is plugged into. Wondering if the motor is creating some AC EMI, given it’s only the screen by the control hub which is affected? We carry SDI over RG6 coax. 
Any suggestions on how we can stop this flickering?? We have limited space and relocating the monitors further away isn’t an option sadly, given their “spotting” function! 

Edited September 20, 2022 by The JC

[timsabre]

Certainly sounds like interference but you need to work out whether it is affecting the monitor itself or the incoming sdi feed. 

Do you have a different type of monitor you could test in that location? 

Alternatively in this sort of problem I've had success by putting an SDI isolation transformer in line with the video cable but they are an expensive thing to try out when you don't know if it'll work.