1143W24E4.00 · EV3 200 Web
03/2021
| 18 |
6. DEFROST
6.1 INTRODUCTION
Defrosting removes ice from the surface of the evaporator. The defrost cycle consists of 4 phases:
1. Defrost;
2. Pre-dripping;
3. Dripping;
4. Post-dripping.
Attheendofeachphase,thecontrollerstartsupthenextone;whentheentiredefrostcycleisfinished,thecontrollerreturns
to normal operation.
With d0
=0,defrostissettomanualoperation.Forautomaticmode,set
d0 > 0.
6.1.1 Types of defrost
The controller can operate with two different types of defrost:
• Modular;
• Standard.
6.2 ADAPTIVE DEFROST
Adaptivedefrostissetbythefollowingparameters:
Par. Description
MU
Range
d0
Automaticdefrostinterval.
0 = Manual defrost only
N.B.: if d8
=3,themaximumintervalisconsidered.
h
0... 99
d8
Defrost interval count mode. 0 = Hours device ON; 1 = Hours compressor ON;
2 = Hours evaporator temperature < d9; 3
=Adaptive;
4 = In real time (RTC).
---
0...4
d9
Evaporation threshold for automatic defrost interval count.
°C/°F
-99.0...99.0
d18
Adaptivedefrostinterval.
0 = Manual only.
min
0...999
d19
Adaptivedefrostthreshold(relativetooptimalevaporationtemperature).
°C/°F
0.0...40.0
d22
Evaporation threshold for adaptive defrost interval count (relative to optimal evaporation
temperature).
°C/°F
-10.0...10.0
6.2.1 Defrost with Hours device ON
Defrost with Hours device ON is set with the following parameters:
Par. Description
MU
Range
d0
Automaticdefrostinterval.
0 = Manual defrost only
N.B.: if d8
=3,themaximumintervalisconsidered.
h
0... 99
d8
Defrost interval count mode. 0 = Hours device ON;
---
0...4
Operation
The controller begins counting the operating hours from when the device is switched on. If d0 >0 and d8
=0,oncetime
d0 has
elapsed,thedevicecarriesoutdefrostofthedurationof
d3.
The d0 count is set to zero (and restarts) every time defrost starts up.
ON
d0
OFF
ON
OFF
d0
d3
d3
ON
Fig. 16.
Modular defrost: Hours device ON
