Copeland EXD-SH1/SH2 Superheat and Temperature Controller

Overview

The Copeland EXD-SH series consists of the EXD-SH1 and EXD-SH2, stand-alone universal superheat and temperature controllers for electrical control valves in air conditioning units and refrigeration systems. The EXD-SH1 controls one valve, while the EXD-SH2 controls two valves in two independent refrigeration circuits. Copeland describes a self-adapting superheat control function when the controller is used with Copeland EX4 to EX8 electrical control valves (and EX4-7 FLR versions) or CV4 to CV6.5 valves, together with Modbus RTU communication, an integrated keyboard with two-line display and a DIN rail housing.

Seven Star LLC supplies the Copeland EXD-SH controllers with matching temperature sensors, pressure transmitters and cables to HVAC and refrigeration contractors, OEMs and facility teams in the Sultanate of Oman and the GCC. Electronic expansion valve control is now common on chillers, rooftop units, cold rooms, supermarket racks and process coolers in Muscat, Sohar and Salalah because it holds superheat tightly across the wide load and ambient swings of the Gulf climate. Our team in Muscat provides engineering support for selection, wiring and parameter set-up.

Operating Principle

As a superheat controller, the Copeland EXD-SH reads suction pressure from a pressure transmitter and suction line temperature from a temperature sensor at the evaporator or economiser outlet. It converts the pressure to saturation temperature for the selected refrigerant, calculates the superheat and drives the stepper motor of the electrical control valve to hold the set superheat. In general terms, this keeps the evaporator well fed without letting liquid reach the compressor. Additional functions include limitation of evaporating pressure (MOP), a low pressure function that behaves like a low pressure switch with alarm conditions, freeze protection based on saturated suction temperature, and manual positioning of the valves.

As a temperature controller, the Copeland EXD-SH maintains a desired temperature by modulating refrigerant mass flow, and no pressure transmitter is required. Control can be set in normal sense, where mass flow increases as temperature rises, or reverse sense, where mass flow decreases as temperature rises. Copeland lists example applications such as temperature control by throttling suction mass flow, hot gas modulation into the evaporator inlet or outlet, discharge temperature control by liquid injection and head pressure control.

Engineering Design of the Copeland EXD-SH

The Copeland EXD-SH controllers operate on 24 V AC/DC ±10%, 50/60 Hz, with power consumption up to 25 VA for EXD-SH1 and 50 VA for EXD-SH2. The housing is self-extinguishing ABS for DIN rail mounting, weighing 320 g, with IP00 protection, so it is installed inside a control panel. Terminals 13 to 36 use removable screw terminals for 0.14 to 1.5 mm² wire supplied with the controller, while terminals 1 to 12 use a 12-pole Molex plug with the EXD-M03 cable ordered separately. The operating surrounding temperature range is 0 to +55 °C with 20 to 85% relative humidity, non-condensing.

Inputs for the Copeland EXD-SH include TP1 NTC temperature sensors (–45 to +150 °C operating range), an ECN-Z60 PT1000 sensor for ultralow temperatures down to –80 °C, PT5B 4-20 mA pressure transmitters or third-party 0.5 to 4.5 V ratiometric transmitters, and dry-contact digital inputs. Outputs include stepper motor drive for EX4-8 and CV4-7 valves, alarm relays rated 24 V AC/DC up to 1 A resistive, and two-wire RS485 Modbus RTU. An optional ECP-024 backup battery or EXD-PM supercap provides backup power to the controller. Copeland warns that the controller is not ATEX approved and must be installed only in non-explosive environments.

Key Features

The following features of the Copeland EXD-SH series are listed in the Copeland technical information.

• EXD-SH1 controls one valve; EXD-SH2 controls two valves in two independent circuits.
• The main function is selectable as superheat control or temperature control.
• Self-adapting superheat control works with Copeland EX4-8 and CV4-6.5 valve series.
• MOP, low pressure, freeze protection and manual valve positioning are built in.
• Many refrigerants are supported, from R134a, R404A, R410A and R32 to R290, R454B, R1234yf and ultralow temperature R23.
• Modbus RTU communication over RS485 allows integration with supervisory systems.
• Sensor and stepper motor wiring failures are detected and alarmed.
• An optional upload and download key copies parameter settings between controllers.

Industrial Applications

Typical applications of the Copeland EXD-SH include superheat control of electronic expansion valves on chillers and packaged air conditioners, economiser circuits on scroll compressors, cold rooms and blast freezers, supermarket refrigeration cases and racks, process coolers and heat pumps. Temperature control mode suits hot gas bypass, liquid injection for discharge temperature control and head pressure control. In Oman, where high ambient temperatures and variable loads challenge mechanical expansion valves, accurate electronic superheat control helps protect compressors and improve system efficiency.

Seven Star LLC supplies the Copeland EXD-SH together with Copeland compressors such as the Copeland ZR125KCE scroll compressor, the Copeland ZR250KCE-TED-522 scroll compressor and the Copeland D3DS5-1500-AWM/D semi-hermetic compressor. Our team in Muscat helps contractors across Oman and the GCC combine controllers, valves, sensors and compressors into reliable systems.

Technical Specifications

The table lists Copeland EXD-SH data from Copeland technical information TI_EXD-SH12_TB_EN (Rev11).

How to Order

To order the Copeland EXD-SH controller, send Seven Star LLC the number of circuits, the valve type and size, refrigerant and the sensors and cables you need. Our team in Muscat will confirm the configuration, share the technical information for download and prepare a formal quotation. Seven Star LLC supplies Copeland compressors and electronic controls to customers in Oman and the GCC with engineering support.