I’m not an electrician. My advice is to always hire a professional when it comes to working with electricity and installing what you need to setup your home mining operation.
Electricity is VERY DANGEROUS and getting it wrong can cause death, fires and serious injury.
When I first started learning about Bitcoin and Bitcoin mining, I quickly realized that it requires a broad understanding of many technologies including cryptography, software, mining hardware, networking, energy and electrical infrastructure.
I’ve spent over 20 years in software technology but had limited access to electricity and power systems analysis. I remember helping my dad in the 80’s wire our cottage with 120V power but that was the extent of my knowledge until recently.
Bitcoin has renewed my thirst for knowledge on power distribution and I’ve been learning about mining focused electrical systems ever since.
If you’re very new to power distribution or have had limited exposure, this post is intended be an introduction focused on power and Bitcoin mining to share what I have learned about electricity and give you a good understanding of the most important concepts and system designs.
Before we jump in, we need to understand the basics of electricity starting with Voltage, Current and Power.
Water Wheel Analogy
A simple electrical circuit like on the left can be viewed similarly to the water system on the right. They both want to turn the fan/water wheel.
- Voltage is the water pressure on the wheel measured in Volts.
- Current is the amount of water flowing onto the wheel measured in Amps.
- Power is the rotational speed of the wheel measured in Watts
The relationship between Voltage, Current and Power is as follows.
Power (Watts) = Current (Amps) * Voltage (Volts)
You can see in the diagram that the electrical current flow, moves like the water flow through the system.
If you want to increase the power to the wheel, you can either increase the water pressure (voltage) or you can increase the amount of water (current) flowing on to the wheel. Both ways increase the power going to the wheel.
In electrical terms, it is better to run higher voltages(higher water pressure) to reduce current(amount of water). Lower current allows for smaller wires and for more capacity for more miners with existing infrastructure as well as increased power supply efficiency.
Electrical Service Type
Generally in Canada and the USA, there are two categories used to describe service types available in most homes and businesses.
- Group #1: 110V, 115V, 120V
- Group #2: 220V, 230V, 240V
The voltages in the same groups can be and are often used interchangeably. The “split-phase” electrical service is the most common coming from the transformer.
This is where the voltage measured from any “hot” wire to neutral (ground) is ~120V and then the voltage measured from one hot wire to another hot wire on a different phase is ~240V.
These voltages coming from the transformers are not constant and vary depending on the number of loads connected to it and the time of day.
It’s rare to measure exactly 240volts coming out of the wire because of this constant fluctuation in voltage. All ASIC miner power supplies are designed to support a wide range of voltages so this fluctuation is managed.
If you want to run any new generation miner, they all require 220V +. The higher voltages can provide the same power with less current, allowing more miners to be powered on the same circuit.
Step 1 – Calculate Maximum Current Demand per miner
Planning capacity for your miners should be done in terms of current(amps). This makes is simple because all circuit breakers, electrical wires, outlets, PDUs and power cords are all rated in amps.
Determine the maximum power consumption in watts of the miner.
For example The power consumption of the Bitmain Antminer S19 pro 110th is 3068Watts. You can find this in the manual or on the manufacturers web site.
Convert Watts to Amps to calculate the worst case current demand.
Current (Amps) = Power (Watts) / Voltage (Volts)
12.78 Amps = 3068 watts / 240 Volts
Step 2 – The electrical panel
The 240V feeder cable from the meter comes into the electrical panel with two Hot wires and one Neutral.
This is where breakers bridge the hot lines coming in with wires going out to receptacles.
Step 3 – Choosing the right circuit breakers
Because miners are running 24/7, you need to ensure that the current demand from your miners does not overload any components on the circuits.
The Electrical Code states that a circuit can only be loaded to a max of 80% of it’s current rating for continuous loads like mining. To determine this we need to calculate the Circuit Derated Current Capacity using the following formula
Circuit Derated Capacity = Circuit Current Rating * 80%
Circuits are rated based on the maximum ampere rating of the circuit breaker and we are using a 20A breaker.
16amp = 20amps * 80%
The derated capacity of a 20amp circuit is 16 amps.
Make sure the total current demand from all miners on the sbrbame circuit do not exceed 80% of the circuit breaker rating.
Rule: Current Demand < 80% Circuit Breaker Current Rating
Step 4 – Choosing the right wires
Electrical wires come in various sizes and are sized using the American Wire Gauge System (AWG).
The smaller the AWG gauge number, the bigger the wire diameter and greater wire current rating.
The higher the amperage rating of the circuit, the larger the electrical wires needed. If the wire current rating is too low, it can cause excess heat that can melt the wire insulation and cause a fire.
You can find the size and the rating printed on the wire insulation.
Make sure the wires you used for your circuits are properly sized.
Rule: Wire Current Rating ≥ Circuit Breaker Current Rating
Make sure the wires’ current rating is greater than or equal to the current rating of the circuit breaker.
Step 5 – Choosing the right receptacles
The receptacle you uses must have a current rating that is not less than the current rating of the circuit breaker.
20Amps is what we decided based on the S19 miner specs.
The Duplex outlets with NEMA 6-20R receptacles that look like this are a good option.
Rule: Receptacle Current Rating ≥ Circuit Breaker Current Rating
Make sure the total current demand from miners on the same receptacle do not exceed 80% of the receptacle’s current rating.
Rule: Current Demand < 80% Receptacle Current Rating
Step 6 – Choosing Power cords & PDUs
Option 1 – Power cord only
The most basic approach to connecting your miner is a properly sized power cord with a NEMA plug on one end and an IEC connector on the other and plug it right into the receptacle.
Option 2 – Using a PDU
A PDU, short for Power Distribution Unit is a device that distributes power from one or more sources to one or more devices.
There are two type of PDUs, the Basic Metered PDUs that display real-time current consumption (amps) for each circuit on a built-in display and there are Smart PDUs that provide more visibility and control of the power distribution to miners.
This Smart PDU is more expensive than the basic ones but provides a lot more features.
- PDU mining pool account connection to view mining rewards on LCD screen in real time.
- monitor and report circuit-level energy consumption (KWH) for all connected miners
- View and access data on the PDU’s self-hosted web application, SSH client, or via HTTP REST API.
- Auto-Detect and Recover Unresponsive Miners using AutoPing feature
- Environment Monitoring with alerting events on power measurements taken by the PDU include voltage rms (VAC), current rms (A), active power (W), apparent power (VA), power factor (PF), line frequency (Hz), energy (KWH), temperature, humidity, and more.
- Overcurrent Detection and Protection to detect, report, and act on overcurrent detections.
- Scheduling Outlets ON/OFF to turn miners off a specific times
When choosing a PDU, there are two main considerations for compatibility with your setup.
- PDU Input Plug Type should match the NEMA plug to connect to the NEMA outlet receptacle installed on the circuit.
- PDU Output Receptacle Types – If your miner has a C20 input, the PDU should have C19 receptacles. If your miner has C14 input, the PDU should have C13 receptacles. Then the connection from the PDU to the miners can be made with standard C14 to C13 or C20 to C19 power cords.
Step 7 – connecting power the miner
Your miner uses a Power Supply Unit or PSU.
The S19 uses an Antminer APW12 PSU that has a voltage range of 200-240V AC. You can see in the picture below, there are two C19 receptacles.
On the S19, the power supply is connected to the side of the miner with the controller on top and the rear and front fans on either side of the has board housing.
C19 to C14 Splitter power cord that is rated for 15 Amps and 220v-250v that plugs into the PSU on the side of the S19 miner.
Here is an example of how it all connects together with a smart PDU. If you only have one miner, you can used the C19 to C14 Splitter and plug nto the Nema 6-20R receptacle.
Step 8 – Connecting the miner to the internet
On the controller there is a Ethernet Connector port for connecting to your router so that the miner can access the Bitcoin network to receive blocks to mine.
Plug an Ethernet cable into this port and connect to your internet or network router.
In Summary
With your miner running, it’s time to configure your miner.
For your S19, follow the step by step instructions in the S19 manual to connect your miner to the Bitcoin network.
Every miner is different and my suggestion is that follow the instructions on how to setup and configure your specific miner.
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