TC4 Series PID Temperature Controller: Model Code Breakdown, Outputs and RS485 Setup

The TC4 series is a panel-mount PID temperature controller with a 4-digit dual-row LED display, universal sensor input and a choice of relay, SSR drive, 4–20mA or SCR trigger output. This page is a specification and commissioning reference; ordering data is on the TC4 product page.

1. Core specification

Parameter	Specification
Models	TC4S / TC4H / TC4W / TC4M / TC4L
Display	4-digit dual row LED — red PV, green SV
Control method	ON/OFF, position control, PID
Input	Thermocouple K, J, E, T, N, S, R, B; RTD Pt100 and Cu50; linear 0–20mA, 4–20mA, 0–5V, 1–5V
Control output	Relay + SSR drive (W), voltage output (1U/2U), current output (1A/2A), SCR trigger (T/P)
Alarm output	0, 1 or 2 alarms
Communication	RS485 Modbus RTU optional (code C)
Supply	100–240VAC (code 2) or 24VDC (code 4), max. 8VA
Accuracy	±0.5% FS
Sampling period	100ms
Relay life	Mechanical >2,500,000 operations; electrical >100,000 operations
Dielectric strength	2000VAC, 50/60Hz, 1 minute
Operating environment	-5 to 40°C, 35–85% RH
Panel sizes	48×48 / 48×96 / 96×48 / 72×72 / 96×96mm
Panel cutout	45×45 / 45×92 / 92×45 / 68×68 / 92×92mm
Depth	75mm body + 4mm bezel

2. Reading the model code

A TC4 order code is built from the size letter, then the output, alarm, communication and supply codes. Confirm each field before ordering, because the output stage is hardware and cannot be changed in the field.

• Size — S (48×48), H (48×96), W (96×48), M (72×72), L (96×96). Choose to match the existing panel cutout on a retrofit.
• Output — W gives both relay and SSR drive; 1A/2A give current output for valves and SCR power controllers; T/P give SCR trigger.
• Alarm — 0, 1 or 2 contacts. Specify at least one for over-temperature indication.
• Communication — C adds RS485 Modbus RTU for PLC or SCADA logging.
• Supply — 2 for 100–240VAC, 4 for 24VDC on DC-powered machines.

The printed TC4/TC5 selection guide on the product page shows every valid code combination.

3. Output selection in practice

Parameter	Specification
Relay	Contactor coils and slow, high-mass loads. Longest cycle time, no panel heat.
SSR drive	Fast PID cycling on extruders, sealing bars and hot runners. Drives a DC-input SSR-DA relay.
4–20mA	Proportional control of modulating valves or an SCR power regulator for stepless heating power.
SCR trigger	Direct pulse drive of a pulse-triggered SCR module.

4. Commissioning

• Set the input type to match the fitted sensor before applying heat, then verify the reading rises during heat-up.
• Set the output type to match the wiring; a relay-wired panel left on SSR output will simply never fire.
• Set the scale high limit and the alarm setpoint below the machine safe limit.
• Run PID auto-tune at the normal working setpoint with the real load fitted.
• With RS485, set a unique station address per controller and match baud rate, parity and stop bits across the bus; terminate the last device.
• Check relay duty: if the contactor cycles faster than roughly once per 30 seconds, move to SSR output to protect contact life.

5. FAQ

Which TC4 fits my existing cutout?

Match the cutout, not the bezel: 45×45mm takes TC4S, 68×68mm takes TC4M, 92×92mm takes TC4L, and the 45×92 / 92×45mm cutouts take TC4H and TC4W respectively.

Can a TC4 run from 24VDC?

Yes, with supply code 4. The AC and DC supply versions are different hardware and cannot be converted later.

Does the TC4 support Modbus?

The C option provides RS485 Modbus RTU for reading PV and writing setpoints from a PLC or HMI.

How do I compare TC4 with TC5?

TC5 shares the same panel sizes and input range and adds the configuration set described in the TC5 setup guide. Full data is on the TC5 product page.

For selection help email sales@strong-ele.com or browse all PID temperature controllers.