Wiring Magnificent Trashcan Supercomputer Circa Laundry Machine

Charg (CHG) Hardware Development
1

WARNING

SERIOUS INJURY, DEATH, OR DAMAGE TO PROPERTY! YOU MUST CONSULT AN ELECTRICAN OR ELECTRICAL ENGINEER!

IMPORTANT Safety Caveat Regarding 120V and Stacked Motherboards:

The reader will take note I did not yet proceed to wiring our stacked motherboard, that means you shouldn’t either (yet). That said, here’s a crude instruction manual for those who are antsy in their pantsy to forge ahead without me, and who are willing to assume the risks sans proper instruction:

And Now, the Main Article

The optional converter which I incorrectly named as such in the video (picture is as a link):

image

Lets talk more about our dryer.

I have selected three wire. I have hot, hot, ground coming from the wall, while the dryer is older and hot hot neutral sharing ground. Is this correct for our design?

Response:

Thanks for clarifying — you’re working with a 3-wire dryer outlet (hot-hot-ground from wall) and an older dryer that expects hot-hot-neutral, where neutral is bonded to ground inside the chassis. Here’s the breakdown:

:electric_plug: What You Have:

  • Wall (3-wire):
    • Hot (L1)
    • Hot (L2)
    • Ground (bare or green — no separate neutral)
  • Dryer (older):
    • Hot (L1)
    • Hot (L2)
    • Neutral (also bonded to chassis ground)

:white_check_mark: Is This Correct? Yes — for legacy installations

Under older NEC code (pre-1996), this was correct:

  • The ground and neutral were allowed to be combined at the appliance end if:
    • You had only a 3-wire branch circuit from the panel (no separate neutral and ground),
    • And the dryer chassis had an internal bonding strap connecting neutral to ground.

So for older homes (or systems wired similarly, like yours), it’s acceptable if:

:warning: The bonding strap inside the dryer remains in place — this connects the neutral terminal to the dryer chassis ground.

:warning: When It’s Not OK:

If you remove that bonding strap and treat the ground wire from the wall as a dedicated equipment ground (rather than neutral), you’ll get unpredictable or unsafe behavior:

  • Dryer won’t run (no neutral for controls or motor),
  • Or worse — stray voltage on chassis.

:light_bulb: For Best Practice (Modern Installations):

Today’s code requires 4-wire dryer outlets:

  • Hot (L1)
  • Hot (L2)
  • Neutral
  • Ground (separate conductor)

But since your wall only has 3 wires, and the dryer is vintage, you’re within spec — just make sure the bonding strap is connected.

:hammer_and_wrench: Summary:

Condition OK? Notes
Wall = 3-wire (H–H–G), dryer = old :white_check_mark: Use bonding strap to combine N–G inside dryer
Wall = 3-wire, dryer = new (4-prong) :cross_mark: Not safe — no neutral path
Wall = 4-wire, dryer = old :white_check_mark: Remove bonding strap; connect N and G separately
Wall = 4-wire, dryer = new :white_check_mark: Ideal setup

Would you like a diagram showing this setup (with bonding strap labeled)?

You said:

is our wire better defined as neutral or ground in the context of the older dryer?

Response:

Excellent and subtle question — and the answer lies in how the conductor functions, not just its name.

:balance_scale: In the context of your older dryer and 3-wire supply (hot-hot-ground):

The third wire (bare or green from the wall) functions as a shared conductor for:

  • Neutral current return path (for 120V controls, light, timer, motor),
  • Equipment ground (bonded to chassis to trip a breaker if there’s a fault).

:brain: So, is it neutral or ground?

:white_check_mark: Functionally: It acts as Neutral (carries return current).
:white_check_mark: Structurally: It’s also the Ground, since it’s bonded to the chassis.

So:

In your case, it’s a dual-purpose conductor — a “grounded conductor” that serves as both neutral and equipment ground.

:fire_extinguisher: This is why the bonding strap inside the dryer is so critical:

  • It intentionally connects neutral to the metal chassis, allowing both roles to be fulfilled safely via one conductor.
  • If you remove the strap and you still only have 3 wires, then the chassis is floating and you have no ground — which is dangerous.

:locked: NEC Terminology (legacy code):

  • It was referred to as a “grounded conductor”, not to be confused with “equipment grounding conductor”.
  • It was allowed to be shared only in existing installations (pre-1996).

Final Verdict:

In your 3-wire system with an older dryer with the bonding strap intact, your third wire is a grounded conductor functioning as both neutral and ground.

If you upgrade to 4-wire later, then neutral and ground must be separated — and the bonding strap must be removed.

Would you like a side-by-side diagram of 3-wire vs. 4-wire dryer wiring?

You said:

lets talk about the relationship between our three wire dryer and the split which attaches to our three wire SPD, and please also go over the strengths and weaknesses of this setup.

Response:

Perfect — you’re now getting into system-level coordination: how your 3-wire dryer setup relates to your 3-wire SPD (Surge Protective Device) on a split-phase 240V system. This is a great junction to analyze grounding, surge protection, code compliance, and overall system behavior.

:gear: SYSTEM OVERVIEW

:light_bulb: Split-phase 240V (U.S. standard residential power):

  • L1 (Hot, 120V)
  • L2 (Hot, 120V, 180° out of phase with L1)
  • N (Neutral = center tap of transformer)
  • Ground (connected to neutral at the main panel only)

:electric_plug: Your 3-wire dryer:

  • L1
  • L2
  • N/G (shared grounded conductor)

Dryer chassis is bonded to this wire — functions as both neutral and safety ground.

:high_voltage: Your 3-wire SPD (Surge Protective Device):

Typically wired:

  • L1
  • L2
  • N or G (usually labeled as “ground” — more on this below)

SPDs work by clamping voltage surges between:

  • L1–L2
  • L1–N
  • L2–N
  • Sometimes also L–G (depending on wiring)

:counterclockwise_arrows_button: How These Systems Relate

Your SPD and your dryer both share a 3-wire connection to the same split-phase system. The key point of interaction is the shared “grounded conductor.”

Component Purpose Role of 3rd Wire
Dryer (3-wire) Power appliance & chassis bonding Neutral return and chassis ground
SPD (3-wire) Clamp surges to safe path Sink surges to ground/neutral

:warning: IMPORTANT: Your SPD assumes the third wire is at a true zero-potential ground reference. But in your 3-wire dryer, it may carry current (as a neutral), not just sit idle like a dedicated ground.

:white_check_mark: Strengths of Your Setup

:check_mark: Simplicity and Compatibility:

  • Your 3-wire dryer is matched to your wall — no adapters, bonding is straightforward.

:check_mark: SPD Still Functions:

  • A 3-wire SPD can still protect between L1–L2 and clamp some L–N surges, even if the third wire is dual-purpose.

:check_mark: Legal for Legacy:

  • NEC still allows continued use of bonded-neutral dryer circuits for pre-1996 installs.

:cross_mark: Weaknesses / Limitations

:warning: Shared Neutral and Ground = Safety Tradeoff

  • If a fault occurs, return current flows through the same path that’s supposed to protect you (ground).
  • This increases risk if that conductor is damaged or high-resistance.

:warning: SPD Less Effective with Shared Neutral-Ground

  • Many SPDs rely on a clean, low-impedance ground reference to function optimally.
  • When neutral and ground are combined, especially at a distance from the panel, this path is “noisier” and less reliable for surge diversion.

:warning: No Dedicated Equipment Ground

  • You lose the safety of a distinct, always-zero-potential ground plane.
  • In the event of a fault in the neutral wire (loose or corroded connection), the dryer chassis can become energized.

:hammer_and_wrench: Mitigations and Best Practices

  1. Keep Bonding Strap in Dryer
  • Vital for completing ground path in a 3-wire system.
  1. Ensure Main Panel Grounding Is Solid
  • Neutral-ground bond must be solid only at the main service panel, never at subpanels.
  1. Minimize Distance Between SPD and Panel
  • Shorter wires = lower impedance = better clamping.
  1. Upgrade to 4-Wire When Possible
  • Especially if you ever redo wiring or replace the dryer.
  • Adds separate, dedicated equipment ground.

:compass: Summary Table

Feature 3-Wire Dryer + SPD
Legal (legacy)? :white_check_mark: Yes
Safe if properly bonded? :white_check_mark: With care
Optimal surge protection :cross_mark: Not fully
Shared return current? :warning: Yes (Neutral + Ground)
Upgrade recommended? :white_check_mark: When rewiring

What if we add enVision EV-20830-L630-GNS Surge Protector/Noise Filter/Power Monitor Nerdgearz LCD between the downstream surge protector Metered PDU 200-240v 30A 30amp L6-30P Cryptocurrency Mining and the upstream splitter which shares the three prong dryer? To clarify, the dryer is downstream the splitter, and the other of the splitter is our filter which itself has the SPD downstream.

Response:

Thank you for this detailed clarification — you’re building a power distribution topology where your 3-prong 240V dryer outlet feeds:

  1. A splitter, which branches into:
  • :basket: Your dryer (legacy 3-wire, hot-hot-grounded conductor),
  • :high_voltage: A filter/SPD/monitor chain powering a PDU and attached mining load.

:compass: YOUR POWER PATH, STEP BY STEP

[Dryer Outlet] (3-prong, 240V, L1-L2-G/N)
        │
    [Splitter]
     /       \
[Dryer]    [enVision EV-20830-L630-GNS]
             │
     [SPD → PDU → Miners]

Let’s break this down with all roles and implications in mind.

:magnifying_glass_tilted_left: DEVICE ROLES IN THIS SETUP

1. Dryer

  • Old-style 3-wire: L1, L2, and shared neutral/ground.
  • Chassis bonding relies on that third wire.
  • Loads are both 240V (heating) and 120V (controls via center-tap “neutral” function).

2. Splitter

  • Physically connects both branches (dryer + monitor/PDUs) to one 3-wire wall plug.
  • All devices share hot-hot-grounded conductor from the panel.

3. enVision EV-20830-L630-GNS

  • Multimode: acts as:
    • Surge suppressor (SPD)
    • Power quality monitor (voltage, current, harmonics, sags, swells)
    • Line noise filter
  • Pass-through device: wired for L6-30 (3-wire 240V)

4. Downstream PDU

  • Accepts filtered 240V power.
  • Provides multiple outlets (probably C13/C19 or L6-20R) to miners.

:balance_scale: SYSTEM ANALYSIS: STRENGTHS & RISKS

:white_check_mark: BENEFITS OF THIS CONFIGURATION

  1. Noise Isolation for Critical Loads
  • The enVision unit can absorb or filter EMI/RFI and transients before reaching sensitive crypto gear.
  1. Metering and Diagnostics
  • Real-time current, voltage, and power quality monitoring helps you catch voltage sags, spikes, and imbalance from the utility or shared dryer circuit.
  1. SPD Layering
  • You now have two layers of surge protection (enVision + downstream SPD):
    • Reduces stress on each,
    • Improves clamping at various stages.
  1. Modular Isolation from the Dryer
  • Even though the dryer and mining gear share a circuit, the enVision device creates a functional separation — no direct contact, lower chance of feedback or interference.

:warning: POTENTIAL WEAKNESSES / CONCERNS

1. Shared Neutral/Ground Still a Limiting Factor

  • All return current from both dryer and filter/PDU flows through the same grounded conductor, whether it’s being used as a neutral (for the dryer controls) or a protective ground (for the PDU).
  • If that conductor becomes high-resistance or open, chassis voltage and safety are compromised.

2. Surge Diversion Path is Not Dedicated

  • SPDs and the enVision need to shunt excess energy to ground — but in your case, that’s also a neutral current path (shared conductor).
  • Result: limited surge clamping effectiveness, especially for L–G or N–G type spikes.

3. Dryer Load Interference

  • Motor startups, heating element cycling, or control noise in the dryer may still introduce harmonics or transients upstream of the enVision unit.
  • The enVision will try to filter this, but it depends on internal design (not all filters block backfeed perfectly).

:toolbox: BEST PRACTICES FOR SAFETY & PERFORMANCE

Action Benefit
:white_check_mark: Confirm dryer bonding strap is intact Ensures safe return path for 120V loads
:white_check_mark: Ensure ground lug in enVision is solid Lets SPD elements shunt safely to chassis
:white_check_mark: Keep wire lengths short from splitter Reduces impedance, improves surge clamping
:white_check_mark: Add inline fuse or breaker for miners Prevents overcurrent draw affecting dryer
:red_exclamation_mark:Avoid simultaneous max draw on both Prevents overheating, nuisance trips
:warning: Monitor neutral voltage drop Warns of shared conductor saturation

:end_arrow: CONCLUSION

Your configuration is sound for a legacy-compliant, shared-circuit setup, with some real-world limitations:

  • Electrically legal, assuming bonding is correct.
  • Safer and cleaner thanks to the enVision filter/SPD.
  • Still grounded on shared conductor, which is suboptimal but manageable.

A developing novel and experimental approach to transient voltage mitigation, particularly considering older ground/neutral bonded (three wire) units split with supercomputers: