PID Bundle Guide: Wiring & Setup
Our PID Value Bundles are designed to save time, both on sourcing parts and on installation. Every controller, solid state relay (SSR) and sensor in a bundle has been checked for compatibility, so it will work as intended. Most bundles are specified for heating processes, controlling resistive AC loads such as elements and cartridge heaters.
This guide takes you through wiring and commissioning a bundle: power supply, thermocouple or PT100 sensor, SSR output, and first-time setup. Treat it as general guidance. Bundles differ, so check the details of yours, and get in touch if you need any support or advice.
Which controllers does this cover? The wiring advice below applies to all the Novus controllers in our bundles (N1030, N1030T, N1050 and N20K48), which share the same standard 9-pin lower terminal block. Check your controller's product manual for any model-specific options.
Safety Notice ⚠
These products require connections to electrical supplies. If you are unsure how to proceed, please consult a qualified electrician or competent person. Consider all parts to be live unless checked and verified as isolated from the supply.
Also consider the heat generated as part of any process. Hot surfaces can cause burns and, in some instances, a risk of fire. Wear PPE as appropriate when installing or operating this equipment. See also our PID Temperature Safety guide.
Controller Terminal Layout
| Terminals | Function | Connect to |
|---|---|---|
| 1, 2, 3 | Sensor input | Thermocouple on 2 & 3, or 3-wire PT100 on 1, 2 & 3 |
| 4 (−), 5 (+) | OUT1, 5V DC pulse | SSR input terminals |
| 6, 7 | OUT2, relay | Alarm lamp, buzzer or contactor coil (where fitted) |
| 8, 9 | Power supply | Single phase 100-230V AC |
1. Power Supply
The majority of our bundles are designed for use with single phase voltages around the 230V AC harmonised standard for the UK and Europe. The product sticker on the reverse of any Novus controller shows its supply voltage. Normally this reads 100-230V, which means a single phase AC supply is appropriate.
NOTE: Applying 400V AC will damage the controller. Three phase UK line to line voltages are not suitable to power the controller.
Terminals 8 & 9 are the standard supply input terminals on the Novus PID controllers in our bundles, and the supply connections should be made here. When using AC, the Live and Neutral can be wired to these terminals in either order.
The controllers draw a very low current when operating, an average rating of 5VA. Rate any fuses or circuit breakers for the control circuit to suit.
CHECK: If you plan to use a DC supply voltage, terminals 8 & 9 are polarity sensitive and must be wired in the correct order.
When the power connections are wired, turn on the supply. The controller display will light up, initially showing the firmware number before moving to the main operating screen.
2. Thermocouple Input
The sensor input terminals on the connector block are numbered 1, 2 and 3. For a thermocouple, only terminals 2 and 3 are required; terminal 1 can be ignored.
Our thermocouple bundles are generally supplied with a Type K thermocouple. The positive wire is often marked with a + or can be identified by its green colour. Check the polarity of the wires and connect them to terminals 2 & 3.
Once wired, set the thermocouple input type in the controller menu. This tells the controller which thermocouple you are using. With power applied, the measured temperature should then show on the main operating screen.
NOTE: Some of our controllers accept a range of different thermocouples. Refer to the product manual or quick guide if you plan to use an alternative thermocouple type.
TIP: Incorrect thermocouple polarity results in a reversed measurement. This can normally be resolved by swapping the wires at terminals 2 and 3.
3. PT100 Input
Our controllers are intended for use with a three wire PT100, which includes a calibration wire to compensate for cable length. A PT100 sensor requires all three input terminals to be wired.
TIP: If you are using a 2 wire PT100 sensor, place a shorting link between terminals 1 & 2. This mimics the calibration wire.
If you use a multimeter to identify the sensor wiring, you should find continuity, or a very low ohms reading, between two of the wires. These two wires go in terminals 1 & 2.
Always make sure the sensor reads correctly: let it warm up and cool down, and check the display moves accordingly.
CHECK: Abnormally high or low sensor readings can be caused by an incorrect sensor type setting in the controller parameters. Always double check the sensor type parameter.
TIP: Offset parameters can be used to compensate for errors in sensor calibration.
Sensor Types And Measurement Ranges
The most common sensor types, the code shown on the controller display, and their measurement ranges:
| Type | Display code | Measurement range |
|---|---|---|
| Thermocouple J | tc J | -110 to 950 °C (-166 to 1742 °F) |
| Thermocouple K | tc K | -150 to 1370 °C (-238 to 2498 °F) |
| Thermocouple T | tc t | -160 to 400 °C (-256 to 752 °F) |
| PT100 | Pt | -200 to 850 °C (-328 to 1562 °F) |
These are the controller's input ranges. The usable range is also limited by the sensor itself, so check the maximum temperature of your probe. For help choosing, see Temperature Sensors Explained.
4. Solid State Relay (SSR)
Our bundles are designed to give a fast output response, which helps give the best accuracy in holding a temperature setpoint. The solid state relay is an important part of this.
Set the control output on the PID controller as OUT1 or OUTA. The output signal is a 5V DC pulse (square wave).
Terminals 4 & 5 on the controller should be wired to the SSR input terminals. Always check and observe the correct polarity.
In the diagram, the input side of the SSR is switched by the control signal from the PID controller. The load could be cartridge heaters or an element. When the input is active, current flows on the load side.
CHECK: Solid state relays generate heat during operation, so plan for the safe dissipation of this heat. Most electrical and electronic components inside a control panel are outside their working range if the ambient temperature is above 40-50 °C. Heatsinks, fans and vents help to maintain internal cabinet temperatures.
The output side of the SSR is normally wired to one or more heating elements. Please note the supplied SSR is only suitable for AC loads.
CHECK: Consider the element size and current draw, and check the cable CSA is appropriate. Cables routed close to sources of heat may need additional protection or different properties, i.e. high temperature cable.
TIP: Our controllers can often drive 2-3 solid state relays from one output. Splitting the load into different "banks" can help with redundancy.
5. Commissioning And General Advice
- Most Novus controllers use a standard 9-pin connector for their electrical connections. It is detachable, which can be helpful when carrying out the wiring.
- Once the wiring is complete, carry out initial testing by simply raising the setpoint above the measured or ambient temperature.
- Check the indications (the lights on the display and on the solid state relay) and note any changes in temperature.
- A fast autotune at 50-60% of the normal working temperature helps to establish the correct PID values.
- A full autotune at normal working temperature can then be carried out if necessary. See PID Tuning and Manual PID Tuning Step By Step.
- Modify the setpoint low and high parameters to keep the temperature within suitable working limits.
- Add alarms for minimum or maximum temperature as appropriate.
- Test the controller with the sensor disconnected. Any signal to the SSR should be lost.
- Add a simple failsafe in case the SSR fails in a closed state.
- Note down or back up your controller parameters for future reference.
- Download and read the full product manual for your controller.
NOTE: Autotuning can lead to some temperature instability as part of the process. We do not recommend autotuning when there is a risk to finished products. Treat autotuning as an offline process.
TIP: When autotuning ovens and kilns, close all doors and access points so the conditions match normal operation.
Sample Drawing: 3kW Single Phase System
A sample wiring drawing for a single phase PID system with a maximum 3kW element. It shows an N1050 controller with a Type K probe on terminals 2 & 3, a 40A SSR on OUT1 (terminals 4 & 5), an alarm lamp on OUT2 (terminals 6 & 7) and the controller supply on terminals 8 & 9. An overtemperature thermostat is recommended in series with the element, and a heatsink is recommended for the SSR.
Frequently Asked Questions
Which terminals does the SSR connect to?
Wire the SSR input to controller terminals 4 (−) and 5 (+), and set the control output to OUT1 or OUTA. The output is a 5V DC pulse, so polarity matters.
Can I power the controller from a three phase supply?
Not line to line. Applying 400V AC will damage the controller. Use a single phase supply of 100-230V AC on terminals 8 & 9.
My temperature reading goes down as the process heats up. Why?
The thermocouple polarity is reversed. Swap the wires at terminals 2 and 3.
Can I use a 2 wire PT100?
Yes. Fit a shorting link between terminals 1 and 2 to mimic the calibration wire. Bear in mind a 2 wire PT100 reads slightly high over long cable runs.
Can one controller drive more than one SSR?
Often, yes. Our controllers can usually drive 2-3 SSRs from one output, which lets you split the load into banks for redundancy.
Download The Guide
Download The PID Bundle Guide (PDF)
Browse all PID Value Bundles, including the Starter, Ramp & Soak, Kiln & Oven Upgrade and N20K48 Bluetooth kits. If you'd like your controller set up before it arrives, see Pre-Programming Of Novus Devices. For anything else, call us on +44 (0)1824 520565. Back to the Knowledge Base.