CPC ESC3 Руководство по установке

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Computer Process Controls, Inc. — ESC3 Installation Guide

ESC3 Overview

The ESC3 is a cost-effective electronic refrigeration controller that provides

control of compressor, fan and defrost management. The ESC3 provides control

of a compressor (or solenoid) valve in response to temperature variations.

The ESC3 comes in two models: a controller with a pluggable 10A relay for

defrost control (P/N 850-3500) and a controller with no defrost relay (P/N 850-

3510).

The ESC3 provides outputs for controlling for defrost and fans. This allows the

ESC3 to be used in applications requiring a defrost signal (as required in electric

defrost systems).

Operation

Temperature Control

Temperature control in the ESC3 is accomplished by comparing the temperature

reading of the case temperature probe against the temperature setpoint. The com-

pressor output is used to control the temperature. If the temperature is above the

temperature setpoint (L1) + the hysteresis setpoint (rd), the compressor output is

turned on (subject to the conditions described in the compressor operation sec-

tion). If the temperature is below the temperature setpoint – the hysteresis set-

point, the compressor output is turned off.

Note that the compressor output can also be used to control a refrigeration sole-

noid to regulate the temperature in a case.

Compressor Control

Several setpoints are available that allow the operation of the compressor output

to be tailored to match individual needs.

Min On/Off Times and Minimum Cycle Time

OFF compressor times can be specified, as well as a minimum time delay

between compressor cycles. These parameters help prevent short-cycling.

Compressor Power ON delay

point (c0) allows the user to specify a delay after the power up of the controller.

The compressor output will not come on regardless of the temperature reading,

until this amount of time has expired.

Compressor Safety Cycle

If the temp sensor fails, the ESC3 can be

programmed to cycle the compressor ON for a fixed amount of time, followed

by a 15-minute OFF time, until the probe failure is fixed. You may also specify

the compressor be fully ON or OFF during probe failure.

Fan Control

The fan output is controlled by the ESC3 based on the current operating mode

(defrost, cooling, etc.) and the setpoints which affect fan operation. It may be set

to run only when required based on case temperature, or it may be set to be

always ON regardless of temperature. In addition to these two basic modes, you

may also turn the fans OFF during defrost, specify the fan will be ON only when

the compressor is running, and delay fan activation after defrost drip time.

Defrost Control

The ESC3 can control the defrost function of a case. The ESC3 executes defrost

cycles at a user-defined time interval. Electric, Off Cycle and Hot Gas defrost

types are supported.

The ESC3 features a number of options to customize operation and termination

of a defrost cycle. A defrost cycle can be terminated based on time or tempera-

ture. When termination by temperature is used, a minimum and maximum

defrost time can be specified.

You may also program the ESC3 to begin a defrost cycle after power-up (after a

user-defined delay time) and initiate a defrost manually (see the description for

"Defrost Key" on this page).

Alarm Control

The ESC3 has several alarm functions. In addition to alarms based on high and

low air temperatures, it will alarm if a probe failure is detected. If you are using

defrost, the ESC3 will also generate an alarm when the defrost cycle did not ter-

minate as expected (such as when the ESC3 is programmed to terminate at a

temperature set point and the set point was never reached).

Interface

The ESC3 features a 3 digit LED display that shows the case temperature. Alter-

nately, the display can be configured to display the product temperature if a

product temperature probe is connected. The temperature can be displayed in

either °C or °F.

1640 Airport Rd. Suite 103 Kennesaw, GA 30144 - http://www.cpcus.com/

Minimum ON/

The compressor power on delay set-

Three keys on the front panel provide an indication of operating status as well as

allowing setpoints to be changed.

Alarm Key

The Alarm key

illuminates when the controller has

detected an alarm condition. This key is also used to reset an alarm condition and

to enter the setup mode (allowing setpoints to be changed).

Compressor Key

The Compressor key

pressor output is on. When the ESC3 is in setup mode, this key is used to select a

setpoint to be modified and to change the value of the setpoint.

Defrost Key

The Defrost key

mode. Press the defrost key for 5 seconds to go into manual defrost mode. The

key is also used in setup mode to select a setpoint to be modified and to change

the value of the setpoint.

Alarm Operation

Indications on the Display

If the defrost, or compressor key blinks.

It means that the corresponding function is delayed by a timing routine or inhib-

ited. Other two-character messages may appear on the screen to indicate changes

of state or alarm conditions:

Code

Air probe has failed

Defrost termination or product probe has failed

Low temperature alarm

High temperature alarm

Defrost timeout has occurred (did not terminate cor-

rectly)

Case is in defrost (not an alarm)

Viewing and Changing the Temperature Setpoint

perature setpoint is the comparison point for the control temperature input. To

change the set point value:

Press the Alarm key for more than 5 seconds until the setpoint is displayed

and blinking.

Press the Compressor key and Defrost keys to raise/lower the value.

Press and hold for five seconds the Alarm key again to accept the new

value.

Changing Other Setpoints

There are two levels of setpoints in the

ESC3. The first level does not require a password to change (unless the buttons

are locked out). The setpoints that can be changed in this manner are identified

in Table 1 (back side) as a USER setpoint. All other setpoint do require a pass-

word to change and are identified in Table 2 (back side) as an OEM setpoint.

To change USER-level setpoints:

Press the Alarm key and hold it until the letters PS are displayed.

Use the Compressor and Defrost key to scroll through the codes for the

different set points (see Table 1 and Table 2).

When the code is displayed for the setpoint you wish to change, press the

Alarm key. The value for that setpoint will be displayed.

Press the Compressor or Defrost key to change the value

Press the Alarm key to go back to the code.

If you have more set points you wish to change, press the Compressor or

Defrost key to scroll to the next USER setpoint and follow steps 3-5.

When finished changing setpoints, press and hold the alarm key for five

seconds until the display stops flashing.

WARNING! If you do not hold the Alarm key for five

seconds after changing set points, the ESC3 will only

temporarily store your setpoint changes -- when the

power cycles to this unit, all setpoint changes will be lost.

To change OEM-level setpoints, the password must be entered. To do this press

and hold the alarm key until the letters PS are displayed. When PS is displayed

release the alarm key and 0 will be displayed. Press the compressor or defrost

keys to enter the password (22 is the default) then press the Alarm key. PS will

be displayed again. At this point, pressing the compressor or defrost key will

scroll through the legend for all setpoints. To change the setpoints, use the iden-

tical procedure that is used to change a USER setpoint.

P/N 026-4700

Rev 1 3/11/05

illuminates when the com-

illuminates when the ESC3 is in defrost

Meaning

The tem-