Emerson EC2-391 Manuel D’Utilisation

Page de 4
EC2-391_65136_EN_R01.doc 
Replacement for 00 
1 / 4  
PCN: 865 022       21.09.2007 
 
 
EC2-391 Display Case and Coldroom Controller 
Operating Instructions 
GB 
Note: This document contains short form instructions for experienced users. 
Use last column in List of Parameters to document your individual settings. 
More detailed information can be found in the User Manual.  
 
The EC2-391 is a dedicated refrigeration controller with superheat and a driver for 
an Alco Controls Electric Control Valve EX2. In addition the EC2-391 controls air 
temperature and manages defrost and fan(s). 
 
 
 
Two ECN-Pxx pipe temperature sensors (1) and (2) measure suction gas 
temperatures at the evaporator inlet / outlet and feed the signals into the superheat 
control loop. The superheat controller output modulates the opening of the EX2 
pulse width modulated Electrical Control Valve (6) thus optimising the refrigerant 
mass flow through the evaporator. The air temperature sensors (3) and (4) measure 
air-in and out temperature of the evaporator and feed signals into the air 
temperature thermostat. The ECN-Fxx fin sensor (5) is used for defrost 
termination. The controller has 3 relay outputs to control the defrost heater (9), the 
evaporator fan (8) and an optional output
 
(7). Please consult the technical data 
(right) for input and output ratings. 
In case of power loss, due to the positive shut-off characteristics of the EX2 
Electrical Control Valves, a liquid line solenoid valve is not needed to prevent 
flooding of the compressor.  
!
  Safety instructions:  
• 
Read installation instructions thoroughly. Failure to comply can result in 
device failure, system damage or personal injury. 
• 
The product is intended for use by persons having the appropriate 
knowledge and skills.  
• 
Ensure electrical ratings per technical data are not exceeded.  
• 
Disconnect all voltages from system before installation. 
• 
Keep temperatures within nominal limits.  
• 
Comply with local electrical regulations when wiring 
Technical Data
 
EC2 Series Controller 
Power supply 
24VAC ±10%; 50/60Hz; Class II 
Power consumption 
20VA max including EX2 
Communication LonWorks® 
Interface, FTT10, RJ45 connector 
Plug-in connector size 
Removable screw terminals 
wire size 0.14 … 1.5mm
2
 
Temperature 
     storage 
     operating 
 
   -20 … +65°C 
 
0 … +60°C 
Humidity 
0…80% r.h.  non condensing 
Protection class 
IP65 (front protection with gasket) 
Pressure transmitter input 
24VDC, 4...20mA 
Output relays               (3) 
SPDT contacts, AgCdO 
 Inductive 
(AC15) 
250V/2A 
 
Resistive (AC1) 250V/8A; 12A total return current 
Triac output for EX2 
Electrical Control Valve 
Coil (ASC 24V only) 
24V AC, 0.1 … 1A  
Marking 
  
 
Mounting 
The EC2-391 can be mounted in panels with a 71 x 
29 mm cutout. See dimensional drawing below for 
space requirements including rear connectors. 
Push controller into panel cutout.(1) 
Make sure that mounting lugs are flush with outside 
of controller housing 
Insert allen key into front panel holes and turn 
clockwise. Mounting lugs will turn and gradually 
move towards panel (2) 
Turn allen key until mounting lug barely touches 
panel. Then move other mounting lug to the same 
position (3) 
Tighten both sides very carefully until controller is 
secured. Do not over tighten as mounting lugs will 
break easily. 
 
 
 
Electrical Installation 
Refer to the electrical wiring diagram (below) for electrical connections. A copy of 
this diagram is labeled on the controller. Use connection wires/cables suitable for 
90°C operation (EN 60730-1). 
 
EC2 analog inputs are for dedicated sensors only and should not be connected to 
any other devices. Important: Keep controller and sensor wiring well separated 
from mains wiring. Minimum recommended distance 30mm.  
Warning:
 Use a class II category transformer for 24VAC power supply 
(EN 60742). Do not ground the 24VAC lines. We recommend to use one 
transformer per EC2 controller and to use separate transformers for 3
rd
 party 
controllers, to avoid possible interference or grounding problems in the power 
supply. Connecting any EC2 inputs to mains voltage will permanently damage the 
EC2.