Overview; General Description; Ordering Code; Quick Reference Guide In Running The Self Adaptive Regulation - Emerson xm678d Operation And Installation Manual

3

Overview

3.1. General Description

The XM678D controller is a microprocessor based
controller for multiplexed cabinets suitable for
applications on medium or low temperature. It can be
inserted in a proprietary Local Area Network (LAN)
with up to eight (8) different sections that can operate,
depending on the programming, as standalone
controllers or by following the commands coming
from the other sections. The XM678D controller is
provided with six (6) relay outputs to control the
solenoid valve, defrost that can be either electrical or
hot gas, evaporator fans, lights, an auxiliary output
and an alarm output, and with the stepper valve driver.
It also has six (6) probe inputs: for temperature
control, defrost end temperature control, display and
the fourth can be used for application with virtual
probe or for inlet/outlet air temperature measurement.
The fifth and sixth probe inputs are used to evaluate
and control the superheat. The XM678D is also
equipped with three (3) free contact digital inputs that
are fully configurable by parameters.
The Hotkey connector allows simple programming of
the controller. The optional direct serial output RS485
that is MODBUS compatible permits simple XWEB
interfacing. Optionally, an RTC is available.
Depending on the model, the Hotkey connector can
be used to connect the X-REP display.

3.2. Ordering Code

Device Name
XM678D
Table 3-1 - Product Ordering Code
2 • XM678D I&O Manual
Emerson Code
318-6600
4 Quick Reference
Guide in Running
the Self Adaptive
Regulation
1. After wiring the XM678D; configure the type of
valve, bipolar or unipolar, via tEu (Default 
tEu = bP: bipolar) and tEP (Default tEP =0)
parameters or through the manual settings. See
Section 6.4., Valve Connections and
Configuration for details.
NOTE: For Alco EX4, EX5, EX6 tEP = 11.
For EX3: tEP = 12
2. Set the proper gas via Fty parameter.
Preset gas is R404A.
LABEL REFRIGERANT
R22 r22
134 r134A
290 r290 - Propane
404 r404A
47A r407A
47C r407C
47F r4107F
410 r410A
448 r448A
Table 4-1 - XM678D Gas Table
OPERATING
RANGE
-58 to 120°F/
-50 to 60°C
-58 to 120°F/
-50 to 60°C
-58 to 120°F/
-50 to 60°C
-94 to 120°F/
-70 to 60°C
-58 to 120°F/
-50 to 60°C
-58 to 120°F/
-50 to 60°C
-58 to 120°F/
-50 to 60°C
-58 to 120°F/
-50 to 60°C
-69 to 120°F/
-45 to 60°C
026-1219 Rev 3