Emerson XM678D, Operation And Installation Manual

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2 • XM678D I&O Manual 026-1219 Rev 3
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
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.
2. Set the proper gas via Fty parameter.
Preset gas is R404A .
Device Name Emerson Code
XM678D 318-6600
Table 3-1 - Product Ordering Code
NOTE: For Alco EX4, EX5, EX6 tEP = 11.
For EX3: tEP = 12
LABEL REFRIGERANT
OPERATING
RANGE
R22 r22
-58 to 120°F/
-50 to 60°C
134 r134A
-58 to 120°F/
-50 to 60°C
290 r290 - Propane
-58 to 120°F/
-50 to 60°C
404 r404A
-94 to 120°F/
-70 to 60°C
47A r407A
-58 to 120°F/
-50 to 60°C
47C r407C
-58 to 120°F/
-50 to 60°C
47F r4107F
-58 to 120°F/
-50 to 60°C
410 r410A
-58 to 120°F/
-50 to 60°C
448 r448A
-69 to 120°F/
-45 to 60°C
Table 4-1 - XM678D Gas Table