⚡ Balboa Expander Board 2-Speed Pump (VS520) – Additional Pump Expansion Module

Compact expansion board to add one 2-speed pump to your VS520 control system with 30A fuse protection.

📋 Product Overview

This PCB is used in some VS520 systems. The Balboa Expander Board for 2-Speed Pump is designed to extend the pump capacity of VS520 control boxes, allowing you to add one additional 2-speed pump to your spa system.

This compact expansion module connects to your existing VS520 main board and provides the additional relay and control circuitry needed to operate an extra 2-speed pump, protected by a 30 AMP fuse for safe operation.

✨ Key Features

✅ 230V / 50Hz Operation – Designed for UK and European electrical systems

✅ 2-Speed Pump Support – Controls one additional 2-speed pump

✅ 30 AMP Fuse Protection – Built-in overcurrent protection

✅ Compact Design – Small footprint at 118mm × 50mm

✅ VS520 Compatible – Designed specifically for VS520 control boxes

✅ BP Series Integration – Works with Balboa BP series systems

🔧 Technical Specifications

Specification	Value
Brand	Balboa
Model / Series	BP
Product Type	Expander Board
Input Voltage	230V
Frequency	50Hz
Pump Support	One additional 2-speed pump
Fuse Protection	30 AMP
Length	118 mm
Height	50 mm

✅ Compatibility Guide

Compatible Control Systems

Control System	Compatibility
VS520 control boxes	✅ Compatible

System Integration

This expander board is designed to work alongside the main VS520 PCB, not as a replacement for it. It adds the capability to control one additional 2-speed pump beyond what the main board supports.

⚙️ Board Functions

Pump Expansion

Function	Specification
Additional Pumps	1
Pump Type	2-speed
Fuse Rating	30 AMP

How It Works

The expander board connects to your VS520 main control board and provides:

• Additional relay control for a 2-speed pump
• High and low speed switching capability
• 30A fuse protection for the pump circuit
• Integration with existing topside panel controls

🛠️ Installation Requirements

⚠️ IMPORTANT: This should be done by an experienced tradesman or a competent individual as a faulty install could result in board damage and invalidate the warranty.

Pre-Installation Checklist

• [ ] Verify you have a VS520 control system
• [ ] Confirm your system requires a 2-speed pump expander
• [ ] Disconnect all power at the isolator/breaker
• [ ] Photograph existing wiring connections
• [ ] Allow capacitors to discharge (wait 5 minutes minimum)

Electrical Requirements

Requirement	Specification
Supply Voltage	230V
Frequency	50Hz
Fuse Rating	30 AMP (provided on board)
RCD Protection	Required (30mA recommended)
Earth Connection	Mandatory

💡 Tip: This board must be installed in conjunction with a compatible VS520 main board – it cannot operate independently.

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⚠️ Safety Warnings

Electrical Safety

• ⚠️ ALWAYS disconnect power before any work
• ⚠️ Installation by experienced tradesman or competent individual required
• ⚠️ Ensure correct voltage supply (230V, 50Hz)
• ⚠️ Verify RCD protection is installed and functioning
• ⚠️ Never operate spa with covers removed from electrical components

Important Notes

• ⚠️ This is an expander board – not a main control PCB
• ⚠️ This PCB is for VS520 control boxes only
• ⚠️ Must not be fitted to any other device/product
• ⚠️ Faulty install could result in board damage
• ⚠️ Faulty install will invalidate the warranty

🎯 Ideal Applications

Application	Suitability	Notes
♨️ VS520 Spa Systems	✅ Direct fit	Primary application
♨️ Multi-Pump Upgrades	✅ Ideal	Add 2-speed pump capability
♨️ Pump Expander Replacement	✅ Direct replacement	For faulty expander boards

This board is designed for:

• Adding a 2-speed pump to VS520 systems
• Replacing faulty expander boards in VS520 systems
• Expanding pump capacity beyond main board limits
• Spas requiring additional jet pump control

❓ Frequently Asked Questions

Q: Is this a main control board or an expander? A: This is an expander board that works alongside your VS520 main control board. It adds the capability to control one additional 2-speed pump.

Q: Can I use this without a VS520 main board? A: No, this expander board requires a VS520 main control board to function. It cannot operate independently.

Q: What size pump can I connect? A: The board supports a 2-speed pump protected by a 30 AMP fuse. Ensure your pump’s current draw does not exceed this rating.

Q: How does this differ from other Balboa expanders? A: This expander is specifically designed for VS520 systems and supports a 2-speed pump with 30A protection.

Q: Can I install this myself? A: This should be done by an experienced tradesman or a competent individual. Faulty installation could result in board damage and invalidate the warranty.

🔄 Balboa Expander Board Comparison

Feature	VS520 2-Speed Expander	Other Expanders
Compatible System	VS520	Varies by model
Pump Type	2-speed	Varies
Fuse Rating	30 AMP	Varies
Dimensions	118mm × 50mm	Varies
Voltage	230V / 50Hz	Varies

🏆 Why Choose the Balboa VS520 Expander Board

• ✅ Genuine Balboa Part – OEM quality and compatibility
• ✅ 230V / 50Hz – Designed for UK electrical systems
• ✅ 2-Speed Pump Control – High and low speed operation
• ✅ 30A Fuse Protection – Built-in overcurrent safety
• ✅ Compact Size – 118mm × 50mm footprint
• ✅ Easy Integration – Connects to existing VS520 system
• ✅ Proven Reliability – Balboa engineering quality

🤝 Why Buy From Parts4Tubs

• ✅ UK-based company with local support
• ✅ Fast UK delivery
• ✅ Expert technical advice from spa specialists
• ✅ Competitive pricing
• ✅ Full warranty support
• ✅ Easy returns within 30 days (unfitted items)
• ✅ Compatible parts and accessories available
• ✅ Help with identifying correct replacement board

Not sure if this is the right expander? Contact our team with your control system details. Please verify you have a VS520 system before ordering.

✨ Summary

The Balboa Expander Board 2-Speed Pump (VS520) is a compact expansion module designed for VS520 control systems. Operating at 230V / 50Hz, this board adds the capability to control one additional 2-speed pump, protected by a 30 AMP fuse. With dimensions of just 118mm × 50mm, it integrates seamlessly with existing VS520 main boards. This is an expander board, not a main control PCB – it requires a VS520 main board to function. Installation by an experienced tradesman or competent individual is required.

Finding and identifying a replacement Hot Tub Circuit Board (PCB)

If you are looking to replace a failed PCB on your Hot Tub’s spa pack, then quite often identifying the part that you need can be the hardest thing.

Firstly, you are looking for a model number on the actual circuit board itself. Having the model or serial of your hot tub is not going to help at this point, you need to find the number on the PCB itself.

Now, with certain brands of PCB, the number of the replacement PCB that you need is not going to match identically the one you are replacing. Why is that I hear you ask?

Well, normally, it is an updated version. This means that it might have updated firmware on the PCB or be a later revision. Normally, this means that the part number would be slightly different. This is usually indicated with a “12345678 -x” at the end of that part number where x indicated a firmware revision.

In some cases, there will be some following letters on the part number of the circuit board, “12345678 -x MAS” this can indicate that the PCB was used for an OEM meaning it was produced for a certain hot tub manufacturer and the letters identify the manufacturer.

This means if you source an original PCB, it will not have the letters, but will in most cases work just fine.

It can be confusing I know!

What if you can’t find a model number?

If you can’t find a model number on the PCB itself, then you need to look for a model number on the spa pack. Normally, there is a sticker on the outside of the spa pack that tells you the current ratings and input voltages etc and this will have a model number.

In general, most spa packs in the USA are manufactured by Balboa, Hydro-Quip, ACC or Gecko. I know I am generalising here, but if you have a spa pack that has the brand of your hot tub on, it will be an OEM so the key is identifying who made the original box.

From there, you can normally find an original PCB that you will be able to switch out.

For example, the Balboa VS (value series) is a very popular spa pack that has been used by multiple hot tub manufacturers under their own brand names. Whatever they have called it, strip it back and it is still a Balboa VS.

Visual Inspection

One of the most important things you can do when you are looking for a replacement is to visually inspect the PCB that you have versus the picture online of the replacement you are considering. They need to look the same even if there are the differences in firmware revisions or OEM part numbers, you should be visually replacing a PCB that looks like the one you have.

Configuring a replacement Hot Tub Circuit Board (PCB)

When you get a new PCB, you are more than likely going to need to configure it. Most PCBs have a number of different modes and setups that the can operate in. For this, you will need to manual or spec sheet to guide you.

For things like DIP switches, most of the time you can copy the settings from your original circuit board.

You may need to move jumpers or even wires to configure voltages – the key here is that you read the schematic and don’t expect the PCB to just work out of the box – it usually doesn’t.

Troubleshooting a Hot Tub Circuit Board (PCB)

Here are some common things you will see when you replace a PCB on a hot tub.

You press the buttons on the topside control and they don’t control the right parts (pumps or blower etc) – this is a mode configuration thing and you will either need to change some DIP switches on the PCB or an internal or low level programming mode on the topside control. Check the manual for how to do this.

To check this, unplug all of your kit – heater, pumps, blower and then turn on the PCB. If it trips with nothing plugged in, usually the voltage is incorrectly set and what is happening is that live current is being sent to the ground – because you have 4 wires into the PCB rather than 3. Current on the ground loop causes the trip. Check the settings to make sure it is configures for 230V.

It might not trip until you physically turn on a pump or a blower.