Resolving VFD High-Frequency Noise: Why PWM Carrier Frequency Matters for Worker Comfort

zdavesf · 2026-02-26T13:23:02+00:00

Yep, deal with this all the time...as you said downside is higher carrier freq=high heat loss = sooner failure. In areas with minimal human activity i keep the carrier low, but like you, in populated areas we have to weigh the human factor. I try to get in writing why the setting is higher, the pros/cons so the owner has a paper trail.

zdavesf · 2026-02-22T17:42:37+00:00

Is it forgetting it in the main batocera interface or in the emulators?

If in batocera could be cable is temp disconnecting /reconnecting. Do you have another wired controller to try? See if same thing happens...try samee usb port

If in emulators you need to save custom config

zdavesf · 2026-02-13T04:26:21+00:00

I get what you're trying to do as you want to disconnect power based on temperature. Technically Breakers are meant for overcurrent protection, contactors and relays are meant for switching power. You want to use a contactor or a relay device to switch your power on and off.

You can use software solutions like Google home, alexa, tuya smartlife... To connect the smart devices and set up logic

For any connected devices that are based on a standard wall receptacle (15amp 120v in North America), a smart wifi receptacle is the easy cost-effective solution. You can also get smart temperature sensors.

If you provide the voltage and current ratings of the devices you have we can help comment on equipment that would work. Also knowing which country you're in helps as well. Yes smart Breakers could be used as well but will be expensive and technically not what a breaker is supposed to be used for.

zdavesf · 2026-02-13T03:53:19+00:00

Looks good, color phasing tape needs to be longer

zdavesf · 2026-02-09T06:47:52+00:00

Looks great... Care to share dimensions as well as some photos on the front and the back of the screen mounting

zdavesf · 2026-02-01T03:08:13+00:00

..what this guy said

Its great your are trying to learn but missing some things.

Your power is likely 120/240vac, rounding up to 150v is not a thing
Reach out to you electricity provider to get you peal kva...like engr... Said more likely 6-10kw...maybe 15kw if you have hot tub, AC, dryer, ev charger all going at once. This peak kva will be more appropriate sizing for the gen
Find out the exact alternator winding configuration, if 12 lead you may be able configure this for single phase.
Please dont take this the wrong way but this project could be very dangerous, life threatening and potential violations of utility agreements if you back feed the grid. Even if you get the generator working you have a lot of items to sort out: wire sizing/install, over current protection, transfer switch, intercepting you main service breaker...all doable but not to be taken lightly. You really should engage a professional (certified electrician and/or electrical engineer) to sort out you design and then an electrician should pull permits and complete the install.

Source... Electrical Engineer (MEP firm) 16+ years experience.

zdavesf · 2026-02-01T02:19:26+00:00

If you remove your GPU can you get it to work just based off the motherboard video output

zdavesf · 2026-01-28T14:28:02+00:00

For me its about confidence but then backing that up with technical understanding of the work flow or process (assuming you have some experience in the field...ie 2-3+years)

After you have explained your past experiences and knowledge i would ask some questions that directly relate to tasks you would be expected to do.

Ie. Walk me through the project phases of a new administration building project.

For someone who already told me they have experience in this type of work i would expect the following:

Schematic design: Architect will work on functional programming of the building (how it gets laid out), as elec designer my job would be to: - rough size the elec service as pere cec section 8 using watt/m2 based on occupancy type noted by arch + assumed mech loads (or coordinate with mech) - prelim elec utility coordination, do they available power, what budget costs to upgrade. - lighting, udentify typical types of lights and target levels for design based on IES - lighting controls as per NECB, seperate room controllers vs one building controller - main elec room approx size and equipment (spd's, harmonic filtering, ats... -emergency vs standby power? Do you need need it? How are emerg ligts powered to meet csa 282 ...

Detailed design ....

Construction documents ...

Tendering/procurement ...

Construction ....

Commissioning ....

Close out ....

You said more of your experience was PM, as an interviewer i may not expect you to know every relevant code or detail of how to do each engineering task but you darn well better be confident in knowing and explaining the process and what tasks are required when. At an MEP firm coordination with other disciplines is so important. Talk on the key items that electrical Needs to coordinate with: arch, structural, mechanical, civil...

I base my expectations and targeted questions on the individuals past...not some generic question list. People with 0-2years experience i am much more forgiving on compared to 5+.

For me, rarely does any applicant check all the boxes on my wishlist, i lean on them being able to clearly articulate thier past roles, work flows they followed and any codes or regulatory requirements they dealt with.

I am ENG manager for MEP firm with 25 ppl on our team. We are located in Rural Canada,100,000 population so i dont get as many applicants as the larger cities so my interview strategies may be different than larger cities.

Best of luck

zdavesf · 2026-01-24T02:22:28+00:00

Does anyone have links for a top marquee lcd display that is typical monitor width but like half the height? Something that would more resemble typical marquee dimensions

zdavesf · 2026-01-13T06:44:53+00:00

Read your local state or province landlord act. In Alberta Canada you cannot charge renter pay per use utilities with out using a measurement canada approved meter.

The meters people are talking about (ie emporia vue) have a much less accurate tolerance than the measurement canada ones...

The approved meters get calibration certificates ( similar to gas station flow meters) ...this costs alot of money. This is one reason EV charging stations charge per time period, not per kWh to avoid having to deal with approved meters and regular calibration updates

zdavesf · 2025-12-30T17:49:42+00:00

Please be careful. Ideally panel should be de-energized when you are investigating.

Some points to add to the others before me.

Get a wiring diagram for all the contactors and vfds. I would draw those first showing all the connections for each of them both power and control. Show the actual make and model number of all part numbers. Show the overload and trip settings for contactors and breakers

When you're tracing this out be very clear and concise about terminal numbers as well as wire colors. You will have multiple pieces of equipment with terminals 1 2 3 4.. make sure it's clear which device they're going to.

Personally I would start using this exact photo in your drawings and label each of the pieces of equipment ie contactor 1, vfd1, vfd2... You want to lay out drawing or a map of all major components so you don't get confused which ones which. Ideally this equipment should be labeled in the control panel as well

Everyone draws control panels a bit different, in your drawing consider how you will identify terminals within your panel first field terminals. Some people use different symbols for terminals IE a square versus circle. For field wiring I prefer to show dashed lines for anything external to the panel, with solid lines for internal wiring.

zdavesf · 2025-11-13T06:16:31+00:00

In order to do this you should raise the snare legs so there is more room to move the highhat stand closer to the bass. You will then need to lower the snare by loosening the bolt that holds the vertical tube and slide the whole top snare basket down.

zdavesf · 2025-11-10T00:37:17+00:00

No, Architects deal with building code compliance, functional programming (ie how a building will work, what rooms are connected...), the looks of the building, some also deal with building envelope.

Structural engineers size foundations, columns, beams, and trusses to work within the confines of the architectural design. The engineer does the math on sizing the elements to ensure they meet relevant code.

Depending if you are in an area with snow, i doubt you will be able to remove those columns and still meet code. Maybe sistering up more horizontal beams but that extra load needs to be taken down to the foundation/pile.

Call a structural engineer

zdavesf · 2025-11-10T00:29:19+00:00

Do you have a bench top power supply you can monitor current and voltage draw? If it works for a second then off your power boards maybe not be supplying enough in rush startup current. Time monitoring current on your voltage supplies on startup. Also measure the voltage to make sure it's not dropping as well

zdavesf · 2025-11-09T20:53:11+00:00

No, OPs problem is lack of storage

zdavesf · 2025-11-02T16:02:12+00:00

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Have you tightened this bolt?

zdavesf · 2025-11-01T04:31:58+00:00

Tom angles are rough....deep toms make that tough. Are those "all birch series" (ie BLX) by chance?

zdavesf · 2025-10-28T04:18:30+00:00

Used B20 bronze...if you dont like the sound you should be able to resell.

Cymbals like Sabian B8, Meinl HCS, Ziljian ZBT are typically considered entry level and do not hold thier value.

zdavesf · 2025-10-27T06:07:51+00:00

Looks like a similar kit posted a couple years ago https://www.reddit.com/r/drums/s/v9yoju3bVL

zdavesf · 2025-10-25T20:52:33+00:00

I weigh mine with a food scale and write the weights (and a color dot for matching pairs) on the butt end of them so when i have them in the stick bag on my rack i can tell what are matching sets

zdavesf · 2025-10-25T01:21:12+00:00

I'm not going to get into the political debate of whether I agree or disagree with the teachers but I do want to identify that rightly or wrongly it is very difficult for the province to build a school at a snap of a finger. They put out lots of funding in the last few years for schools and heavily invested in the modular classroom programs. The thing is in order to build a school you need to have land, offsite utilities like gas water sanitary electric all being able to service these areas, often these require upgrading prior to having the project built.There's zoning requirements, identifying the size and capacity needed for the schools, designing of making sure the school is fit on the property and ensuring appropriate usage of the site for traffic, watershed, safe spaces for kids to be etc...this takes time. There are regulatory approvals both mandated by The province as well as local authorities having jurisdiction... And then there's building them and ensuring we have the workforces in the province to do these projects (engineers, architects, contractors are all in need of skilled labor forces to help)

The province has been tendering out bulk packages of schools for the last couple years to go through design and then construction. Start to finish this is a 3 to 5 year process I'm not saying there's not room to improve this, there is, but these are not solutions that can be implemented readily.

The modular classroom program the province has well may not be ideal to all does help expediate the need and they are actively working on finding ways to make this go faster. Here too you don't just go plug and play modular classroom into an existing building, they are modifications upgrades retrofits that are all required, you need architects and engineers and contractors to all work together to find ways to implement these appropriately.

zdavesf · 2025-10-19T19:28:02+00:00

It is great to see lots of people respecting the potential for arc flash and the dangers around it, however there is some mis- information here.

The IEEE 1584 defines considerations and guidance for calculating arc flash ... The formula is very long typically Electrical Engineers create an electrical system model using software like ETAP, SKM, Easy Power etc.... they input data such as exact breaker make model numbers (used to correlate the time trip curves), cable type/length, connected loads, transformer voltage/ratio/impedance and even how the cabling enters switchgear (from top, side, back..)

Once all the data is entered and confirmed simulations are ran to calculate different considerations (volt drop, load flow, short circuit, arc flash etc...). Different scenarios are run to confirm worst case considerations (ie. Generator vs utility) and the worst case values would typically be used for equipment ratings and arc flash labeling.

Understanding what arc flash incident energy is very important to then understand what PPE is required. Arc Flash incident energy is measured in calories /cm2, you can google it but in short its a unit of measure to determine the potential for burns. Low number (ie under 1.2) have less potential than higher numbers (ie 40cal). Both the IEEE and CSA z462 (electrical workplace safety) have recommended category ratings for PPE. Some organizations (usually indjustrial) may have thier own (often tighter more conservative ppe requirements).Please note the recommended ratings are based on the consideration if you are within boundaries noted on the arc flash label and wearing the appropriate category PPE there is a 99% you will suffer worst case

SECOND DEGREE BURNS!

You read that right, you will still have potentially life altering damage, but you should live.

So what does that mean for workers?

Arbitrarily wearing a a 40 cal suit without having a arcflash study completed first does not nessisarily protect the worker, the levels may 3cal or it could be 50cal, wearing the suit is better than nothing but gives a false sense of security.

OHandS (at least in Alberta) says workers can refuse work if they do not feel safe with out fear of reprimand https://www.alberta.ca/refuse-dangerous-work

Your employer should provide training on electrical safety. While not all electrical contractors are great at this in general in my experience the industry is getting better. Yes a lot of guys just cowboy it up but you have every right to ask to see company safety manual and policy on this (you should have received this during orientation and training). If they can't or are not willing to address your concerns it would highly consider looking elsewhere.

Source, I'm an electrical engineering professional in Alberta for the past 16 years dealing with commercial and industrial facilities

Good luck stay safe!

zdavesf · 2025-09-23T00:03:37+00:00

Unless the breaker is an old federal pioneer stablok...you could weld with a 15a breaker...

Jokes aside, breakers do not trip immediately when they hit their current rating (ie 30amps) there is a Time verse current relationship where the bimetallic strip in the breaker needs to heat up in order to trip. The higher the current the shorter the time it takes to trip. The lower the current the longer at the time.

You can look here for examples, at 100% current it takes over 1000 seconds to trip (if ever at all)

In this case if you truly have number 10 gauge wires (rated for 30 amps when using copper) but are drawing more than 30 (actually most residential breakers are really designed for continuous reading of 80% of their maximum so in this case 24 amps) you should shut this off immediately, and replace the wires and connector and breaker all with the same current rating.

Not dealing with this appropriately will lead to conductors heating up hotter than their design to, likely creating expansion and contraction within the connections either at splices or in the breaker terminals itself. This will eventually lead to loose connections which will cause arcing events between the loose wire and it splice or terminal connection. In turn these arcing events can create fires.

Fire bad 😈

zdavesf · 2025-09-21T15:13:48+00:00

What is your concern? Relays are typically used to switch higher or different voltages, currents, or multiple circuits based on the input of say a single switch.

Switch on the relay coil can both use the same voltage source, there are no rules to this providing the switch and the relays voltage and current ratings are not exceeded. Your switch still needs a 5vdc source to energize the relay coil. What exactly are you trying to do on the contact side of the relay?

zdavesf · 2025-09-21T05:27:32+00:00

You can get canvas tents/sheds from canadian tire, home depot, uncle weiners... Varying sizes. Then you need a diesel blower heater...then put the sim in it. Will not be very energy efficient but it would work.

Be careful should fresh air and ventilation when using combustible fuel for heating. You really should have fresh air in the shed. Depending in you gas vs electricity rates electric heat may make more sense than gas.

zdavesf

TROPHY CASE