VP Cable Options
Variopin (VP) electrical connectors are unique to process sensors. Their design is well suited for sensor applications since VP connectors have no recessed areas where moisture can collect. They also maintain a robust IP68 rating and withstand repeated autoclave cycles. Hamilton makes three varieties of open-end VP cables. Each cable design is described below along with its intended purpose and sensor products.

VP6 Open End Cables
These cables are recommended for use with traditional (non-Arc) products such as pH / ORP, polarographic DO, and 2 / 4 pole Conducell conductivity sensors. These products have analog (mV, nA) output signals. The measurement signal is carried on a single coaxial cable. VP6 cables use a slightly heavier outer insulation jacket that can be desirable in rough environments

Sensors with VP6 connections will have 6 gold contact pins as shown in the picture to the left. The measurement pins are always A & B on either side of the keyed notch. Matching cable product numbers are listed below.
Wire Color & Description | VP Pin | pH/Redox | OxyFerm VP / OxyGold | Conducell UPW | Conducell 4UxF |
---|---|---|---|---|---|
Black transparent coax core | A | pH/Redox | Cathode | Inner Electrode | High Potential |
Red wire | B | Reference | Anode | Inner Electrode | High Current |
Grey wire | C | - | - | Outer Electrode | Low Potential |
Blue wire | D | Liquid Earth | Ground | Outer Electrode | Low Current |
White wire | E | Pt 100 / Pt 1000 | NTC 22 kOhm | Pt 1000 | Pt 1000 |
Green wire | F | Pt 100 / Pt 1000 | NTC 22 kOhm | Pt 1000 | Pt 1000 |
Green/yellow wire | Housing | Shield | Shield | Shield | Shield |

VP8 Open End Cables
VP8 cables are designed for use with the VisiFerm ECS Optical DO sensors. The cable uses a double coaxial design to provide additional shielding of the measurement signal from the power wires needed for the optical measurement. Due to this shielding, the VP8 cables are also popular with pH / ORP as well as polarographic DO measurements in electrically noisy environments.

Pin connections on VP8 sensors follow the same pattern as VP6 but have the additional two contact pins needed to carry power for the sensor. Matching cable product numbers are listed below.
Wire Color & Description | VP Pin | VisiFerm ECS (ECS mode) | VisiFerm ECS (mA mode) | Oxyferm VP / OxyGold | pH / Redox |
---|---|---|---|---|---|
Black transparent coax core | A | Cathode (ECS Mode) | - | Cathode | pH/Redox |
Black coax shield | B | Anode (ECS Mode) | - 4 to 20mA | Anode | Reference |
Red transparent coax core | C | Power: +24VDC | Power: +24VDC | Guard | - |
Red coax shield | D | Power: Ground | Power: Ground | Ground | Liquid Earth |
White wire | E | NTC 22 kOhm | - | NTC 22 kOhm | Pt 100 / Pt 1000 |
Green wire | F | NTC 22 kOhm | - | NTC 22 kOhm | Pt 100 / Pt 1000 |
Yellow wire | G | RS485 Rx (A) | - | - | - |
Brown wire | H | RS485 Tx (B) | - | - | - |
Green/yellow wire | Housing | Shaft | - | Shield | Shield |

VP8 Data Cables
Data cables are easily distinguished by their reddish orange insulation. These cables were specifically designed for use with Hamilton Arc sensors which output Modbus digital protocol and 4 - 20 mA output signals. Data cables use individual wires (no coaxial cable) thus should not be used with traditional analog sensors.

Arc sensors only use the VP8 style connector head shown to the left. Matching cable product numbers are listed below.
Wire Color & Description | VP Pin | pH/ORP, OxyFerm, Conducell Arc | VisiFerm Arc | Incyte Arc |
---|---|---|---|---|
yellow wire | A | 4 to 20mA interface #2 | - | - |
Green wire | B | 4 to 20mA interface #1 | 4 to 20mA interface #1 | - |
Red wire | C | Power: +24VDC | Power: +24VDC | Power: +24VDC |
Blue wire | D | Power: Ground | Power: Ground | Power: Ground |
Brown wire | E | - | - | |
White wire | F | - | - | |
Grey wire | G | RS485 Rx (A) | RS485 Rx (A) | RS485 Rx (A) |
Pink wire | H | RS485 Tx (B) | RS485 Tx (B) | RS485 Tx (B) |
Green/yellow wire | Housing | Shield | Shield | Shield |
Related Content
- Connecting Arc sensors to PLCs (Programmable Logic Controllers)
- Visit the cable section of our website for further help with selection
- New to process sensors? Visit our General Sensor Article Page to see similar content.