Chromalox C4 Four-Zone SCR Power Controller

Four-zone SCR power controller for electric heating loads

The Chromalox C4 combines four universal process inputs, four independent heat/cool PID loops and the SCR (solid-state relay) power stage in one DIN-rail or panel-mounted unit. It manages single-phase and three-phase heating loads that need zero-cross firing, with a current transformer on each loop so that the controller can watch the load as well as the temperature. Typical uses listed by Chromalox include extrusion, thermoforming, injection molding, heat treatment, mold heating, multizone furnaces and packaging lines.

Each zone is monitored for loop break, heater break, SSR short circuit, sensor opening or short circuit and over-temperature, so failures can be corrected before they stop production. The C-PWR configuration software supports trends, historical data and parameter cloning, and the optional C4-OP local interface (three 4-digit displays, IP65) stores configurations for up to ten C4-family devices.

Technical specifications

Ordering code and options

A typical model number reads C4-304D4-F00. The first block is the current per loop at 40 °C ambient, continuous service from 110 to 480 VAC: 164 (16 A), 304 (30 A) or 404 (40 A). The auxiliary output letter is O (none), R (relay), D (logic), A (analog) or T (triac). The auxiliary input digit is 2 for four current transformers or 4 for four CTs plus four linear inputs, which is not available with the EC, PN and ER fieldbus codes. The fusing character is 0 (none) or F (fuse holder with extra-rapid fuses), and F is not available with the 404 size.

The last two characters choose a second fieldbus: 00 none, MR Modbus RTU, ET Modbus TCP/Ethernet, ER EtherNet/IP, PB Profibus DP, PN PROFINET, EC EtherCAT, CN CANopen, DN DeviceNet or EM Euromap 66. Listed accessories include a USB to RS485 communication cable (PCN 309180), a serial Modbus RJ10 connection cable (307096), the C4-OP operator terminal with a 0.2 m cable (307117) and a 24 VDC 12 W power supply (0081-10091).

Selecting a C4 for a heating panel

Choose the size from the heater current per zone at the supply voltage, remembering the 16, 30 and 40 A per-channel limits at 40 °C, and move to the C4X data sheet for higher currents. Decide the fieldbus before ordering, because the card can be fitted at order or added later. Confirm the load wiring (single, dual or three phase), the sensor types, whether fuse holders are wanted and the available ventilation, since SCR stages dissipate heat. For simpler on/off switching of single loads see the contactors and relays range, for example the Carlo Gavazzi RM1A48D50 solid state relay.

Documents and quotation

The Chromalox C4 model sheet is attached and carries the electrical, wiring-option and ordering tables. Seven Star LLC is an independent supplier in Muscat; send the complete model number, quantity and load data for a quotation, with stock and lead time confirmed at quotation.