# 8V1016 Servo Drive Cannot Reset Below 200 VAC **URL:** \ **Category:** B&R Software & Runtime\ **Tags:** automation-studio\ **Created:** [August 17, 2026, 7:06pm UTC](https://community.br-automation.com/t/8v1016-servo-drive-cannot-reset-below-200-vac/12332 "2026-08-17T19:06:34Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![kevin1127](https://avatars.discourse-cdn.com/v4/letter/k/FF8800/32.png) [@kevin1127](https://community.br-automation.com/u/kevin1127)\ **Post date:** [August 17, 2026, 7:06pm UTC](https://community.br-automation.com/t/8v1016-servo-drive-cannot-reset-below-200-vac/12332/1 "2026-08-17T19:06:34Z")
Hi Team Our four-lane stick-pack machine uses four B&R 8V1016 servo drives for the auger motors. The machine has a 208 VAC three-phase power supply. When the input voltage drops below approximately 200 VAC, the drives show a “DC bus low voltage” fault and cannot be reset. When the voltage increases above 200 VAC, the drives can usually be reset and enabled. Is it possible to adjust the undervoltage threshold setting for the 8V1016 drives? If this setting can be changed, could you please advise: 1. Which parameter controls the undervoltage threshold? 2. Which version of B&R Automation Studio is required? 3. Can the parameter be changed online without the original PLC project? 4. Is lowering this threshold safe and supported for a 208 VAC three-phase supply? The machine project appears to be from around 2016, and the system information may indicate Automation Studio 2.7. ---
**Author:** ![valerio.manenti](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/valerio.manenti/32/11712_2.png) [@valerio.manenti](https://community.br-automation.com/u/valerio.manenti)\ **Post date:** [August 17, 2026, 11:18pm UTC](https://community.br-automation.com/t/8v1016-servo-drive-cannot-reset-below-200-vac/12332/2 "2026-08-17T23:18:13Z")
> [@kevin1127](#): > > DC bus low voltage ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/0/0d48e25284031ddae18dee19f29a460e31578f66.png) Before to change anything trace the ParID 298: ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/a/a8f51af742eccd03e0d6757dd11cd6f6b1c57027.png) > Which parameter controls the undervoltage threshold? With the ParID 300 you can read and write, if you want, the lower limit of voltage detection: ![image](https://europe1.discourse-cdn.com/brcommunity/original/2X/a/ab8f7905a9390402b0d6fd059c2c132d162c02f9.png) > Which version of B&R Automation Studio is required? most important is the ACP10 version installed on the drive. > Can the parameter be changed online without the original PLC project? Normally I do that with the original prj, so I’m not the correct person for this question. > Is lowering this threshold safe and supported for a 208 VAC three-phase supply? Well first you have to consider how low voltage affects performance: _Small help from AI:_ a) **Reduced Maximum Speed:** The maximum achievable speed (RPM) of a motor is directly proportional to the DC bus voltage. If the voltage drops, the motor cannot spinning at its full rated speed. b) **Decreased Maximum Power:** Because power is the product of speed and torque, limiting the speed naturally limits the total mechanical wattage output. c) **Risk of Overheating:** If you force the motor to maintain its original mechanical load or speed, a motor controller (like a VFD or servo drive) will try to compensate by pushing **more current (Amps)** into the windings. High current generates severe heat, which can quickly degrade winding insulation. d) **Stalling Under Load:** At lower voltages, the starting torque drops. If the load requires more torque than the motor can produce at that voltage, the motor will stall. A stalled motor draws massive current and will burn out if not shut down by a protective trip. Ciao Valerio ---
**Author:** ![kevin1127](https://avatars.discourse-cdn.com/v4/letter/k/FF8800/32.png) [@kevin1127](https://community.br-automation.com/u/kevin1127)\ **Post date:** [August 18, 2026, 12:06am UTC](https://community.br-automation.com/t/8v1016-servo-drive-cannot-reset-below-200-vac/12332/3 "2026-08-18T00:06:46Z")
Thanks, Valerio. The version for the stickpack studio is V2.7. Currently, the download is not available online. I called B&R Canada, and they said they would send it to me. But I have not got yet. ---
**Author:** ![valerio.manenti](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/valerio.manenti/32/11712_2.png) [@valerio.manenti](https://community.br-automation.com/u/valerio.manenti)\ **Post date:** [August 18, 2026, 1:33am UTC](https://community.br-automation.com/t/8v1016-servo-drive-cannot-reset-below-200-vac/12332/4 "2026-08-18T01:33:54Z")
Don’t worry @kevin1127 , you’ll receive AS 2.7 soon; getting AS 2.7 is the easy point in your to do list 🙂 Ciao Valerio ---
**Author:** ![valerio.manenti](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/valerio.manenti/32/11712_2.png) [@valerio.manenti](https://community.br-automation.com/u/valerio.manenti)\ **Post date:** [August 19, 2026, 4:30pm UTC](https://community.br-automation.com/t/8v1016-servo-drive-cannot-reset-below-200-vac/12332/5 "2026-08-19T16:30:22Z")
Case reported to our Support in US/CA, we will update the Community at the end of our investigation. Ciao Valerio ---
**Author:** ![valerio.manenti](https://dub1.discourse-cdn.com/brcommunity/user_avatar/community.br-automation.com/valerio.manenti/32/11712_2.png) [@valerio.manenti](https://community.br-automation.com/u/valerio.manenti)\ **Post date:** [September 3, 2026, 10:59pm UTC](https://community.br-automation.com/t/8v1016-servo-drive-cannot-reset-below-200-vac/12332/6 "2026-09-03T22:59:35Z")
Thanks Kevin for your final feedback: _“We solved the problem via setting change for transformer in the building, the whole panel got 208VAC so the machine worked properly”_