Danfoss MCX-RTU User guide

User Guide

MCX-RTU

Rooftop unit

User Guide | MCX-RTU Rooftop

Contents

Document history........................................................................	3
Product Introduction...................................................................	3
Ordering........................................................................................	3
Specifications...............................................................................	4
Approvals......................................................................................	4
Installation....................................................................................	5
Connections..................................................................................	6
Network Topology........................................................................	8
Sequence of Operation................................................................	9
Cooling Mode.....................................................................................	9
Heating Mode...................................................................................	10
Dehumidification Mode................................................................	10
CO2 Mode...........................................................................................	11
DOAS Mode.......................................................................................	11
Status Screens............................................................................	12
Configuration.............................................................................	14
Overrides....................................................................................	24
Schedule Enable.........................................................................	25
How it works......................................................................................	25
Backup / Restore.........................................................................	26
Purpose...............................................................................................	26
How it works......................................................................................	26
Using More Than One Zone Sensor...........................................	26
Data Logging..............................................................................	27
How it works......................................................................................	27
Broadcast Configuration...........................................................	28
How it works......................................................................................	28
Configure Sensors...........................................................................	28
Configure Schedules......................................................................	28
Configure Load Shed......................................................................	28
AK-SM 800 MCX-RTU Commission............................................	29
IO List..........................................................................................	34

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Document history

Product Introduction

Version	Init.	Date	Description
1.00	FF	12/01/15	Initial MCX-RTU User Guide
1.04	FF	7/31/2018	Firmware v1.04 Update

Ordering

The MCX-RTU controller is a complete solution for controlling a small to medium sized commercial rooftop unit. The controller provides energy efficient control of the rooftop while maintaining designed comfort levels and safety of the controlled space. It is also designed to complement the Danfoss full store control via the connection to the AK-SM 800 series front end.

Type	Function	Application	Code no.
MCX-RTU	Controller for small to medium sized	Rooftop Controller	080G0304
	rooftops
MCX08M2	Optional additional IO for MCX-RTU	IO Expansion	080G0307
MMIGRS2	Optional Remote Display	Remote Display	080G0294

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Specifications	Supply Voltage
	85 – 265 V AC, 50/60 Hz Maximum power consumption: 27 W, 48 VA insulation between power
	supply and the extra-low voltage: reinforced
	Modbus
	It is important that the installation of the data communication cable be installed correctly.
	Remember to terminate each end of the bus. EIA485 Rated cable must be used.
	See separate literature No. RC8AC902.
	DO - Digital outputs, 15 pcs. DO1 – DO15
	DO1 - DO15, all are mechanical relays, no solid state relays
	AO - Analog output, 6 pcs. AO1 – AO6
	Outputs are 0 – 10 V DC by default
	AI - Analog Inputs, 14 pcs. AI1 – AI14
	All temperature sensors default to PT1000, Pressure transducers default to .5 – 4.5 V DC
	ratiometric with 5 V DC supply. All other inputs are 0 – 5 V DC by default
	DI - Digital switch inputs DI1 – DI17
	All Dry contacts except DI17 (24 V AC or 230 V AC driven)

Approvals

AK-SM 800 Firmware required to interface with the MCX-RTU must be VG8.033 or greater and StoreView Desktop version 1.13 or greater must be used for remote access.

EU Declaration of Conformity

This product is in conformity with the following directive(s), standard(s) or other normative document(s), provided that the product is used in accordance with our instructions.

EMC directive 2014/30/EU

By fulfilling the requirements in the following standards

EN 61000-6-4: 2007 + A1: 2011 Generic standards. Emissions standard for industrial environments EN 61000-6-2: 2005 Generic standards. Immunity for industrial environments

and

LVD directive 2014/35/EU

By fulfilling the requirements in the following standards

EN60730-1: 2011 Automatic electrical controls for household and similar use. General requirements

EN60730-2-9: 2010 Particular Requirements for Temperature Sensing Controls

and

RoHS Directive 2011/65/EU

By fulfilling the requirements in the following standards EN 50581:2012

UL Approval

UL file: E31024

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Installation

The MCX-RTU is mounted on a DIN rail with enough room to easily connect power and other interface wires.

This image provides the dimensions of the MCX-RTU controller for determining space for mounting. Make sure that you allow enough space for easy routing of the required interface cables for power, inputs and outputs.

<![if ! IE]> <![endif]>110
280	63

The MCX-RTU must be mounted in a space that meets the environmental standards named in the specification section of this document.

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Connections

Wiring Diagram MCX 152V - top and bottom

MCX152V - TOP

AK-SM 800 Modbus connection

VLT Drive

Modbus connection

Mixed Air (PT1000)

Outdoor Temp (PT1000)

Light Level (5VDC)

Compr. 1 Press (5VDC)

Compr. 2 Press (5VDC)

Compr. 3 Press (5VDC)

Compr. 4 Press (5VDC)

COM 1

D1 +

D1 -

COM 2

D2 +

D2 -

AI 8

AI 9

AI 10

AI 11

5V+

15V+ COM

COM

AI 12

AI 13

AI 14

<![if ! IE]>

<![endif]>2-RS485 1-RS485

<![if ! IE]>

<![endif]>14-8 INPUT ANALOG

<![if ! IE]> <![endif]>MOTOR2	<![if ! IE]> <![endif]>STEPPER
<![if ! IE]> <![endif]>MOTOR1	<![if ! IE]> <![endif]>STEPPER
	<![if ! IE]> <![endif]>CARD MEMORY
	<![if ! IE]> <![endif]>6-1 OUTPUT ANALOG

<![if ! IE]>

<![endif]>7-1 INPUT ANALOG

ST2 4

ST2 3

ST2 2

ST2 1

Not used

ST1 4

ST1 3

ST1 2

ST1 1

<![if ! IE]>

<![endif]>SD/MMC

AO 6		Damper AO
AO 5		VS compressor 4
AO 4		VS compressor 3
COM
AO 3
AO 2		VS compressor 2
AO 1		VS compressor 1
COM		Fan AO
AI 7		DP Outside/Mixed Air
AI 6		Zone CO2 (0-5V DC)
AI 5		Outdoor RH (0-5V DC)
COM
COM
15V+
5V+
AI 4		Zone RH (0-5V DC)
AI 3		Return Air (PT1000)
AI 2		Supply Air (PT1000)
AI 1		Zone Temp(PT1000)

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Wiring Diagram MCX 152V - top and bottom

Input Voltage

110-230 V AC

Stepper Backup

NOT USED

Fan Proof

Phase Loss

Shutdown 1

Shutdown 2

Fan Drive Fault

Compr 1 Drive Fault

Compr 2 Drive Fault

Compr 3 Drive Fault

Compr 4 Drive Fault

Filter Clogged Fault

Damper Override

Title 24

Schedule Override

Cool 1 Proof

Cool 2 Proof

Cool 3 Proof

Reheat (N.O.)

Damper (N.O.)

Heat Reclaim 1 (N.O.)

Heat Reclaim 2 (N.O.)

Heat Pump (N.O.)

Fan Low Speed (N.O.)

Fan High Speed (N.C.)

N						<![if ! IE]> <![endif]>POWER SUPPLY
L
COM						<![if ! IE]> <![endif]>STEPPER
+ BATT						<![if ! IE]> <![endif]>BACKUP
15V+
COM
DI 1
DI 2						<![if ! IE]> <![endif]>DIGITAL
DI 4
DI 3						<![if ! IE]> <![endif]>1INPUT
DI 5
COM
DI 6			<![if ! IE]> <![endif]>8-
DI 7
DI 8
COM
DI 9
DI 10						<![if ! IE]> <![endif]>DIGITAL
DI 11
DI 12						<![if ! IE]> <![endif]>9INPUT
DI 13
COM
DI 14			<![if ! IE]> <![endif]>16-
DI 15
DI 16
DI 18H						<![if ! IE]> <![endif]>DIGITAL
DI 18						<![if ! IE]> <![endif]>INPUT
COM 18
			<![if ! IE]> <![endif]>18
C 9
NO 9						<![if ! IE]> <![endif]>DIGITAL
C 10
NO 10						<![if ! IE]> <![endif]>-9OUTPUT
NO 11
C 11
			<![if ! IE]> <![endif]>12
C 12
NO 12
C 13
C 13
NO 13						<![if ! IE]> <![endif]>DIGITAL
NC 13
						<![if ! IE]> <![endif]>-13OUTPUT
C 14
NC 14
NO 14
C 15			<![if ! IE]> <![endif]>15
NO 15
NC 15

MCX152VBOTTOM

			COM
<![if ! IE]> <![endif]>CAN			CANL
			CANH
			R120
<![if ! IE]> <![endif]>-CAN			CAN-RJ
<![if ! IE]> <![endif]>RJ
<![if ! IE]> <![endif]>ETHERNET			ETH
<![if ! IE]> <![endif]>DIGITAL			COM 17
<![if ! IE]> <![endif]>INPUT			DI 17
			DI 17H
<![if ! IE]> <![endif]>17
<![if ! IE]> <![endif]>DIGITAL			NO 8
			C 8
<![if ! IE]> <![endif]>-6OUTPUT			NO 7
			NO 6
<![if ! IE]> <![endif]>8			C 7
			C 6

Optional IO

Expansion

Optional -

Remote Display

Not Used

Cool 4 Proof

Aux Heat 4 (N.O.)

Aux Heat 3 (N.O.)

Aux Heat 2 (N.O.)

		NO 5			Aux Heat 1 (N.O.)
		C 5				Cool 4 (N.O.)
<![if ! IE]> <![endif]>DIGITAL		NO 4
		C 4
<![if ! IE]> <![endif]>5-1OUTPUT		NO 3			Cool 3 (N.O.)
		C 3					Cool 2 (N.O.)
		NO 2
		C 2					Cool 1 (N.O.)
		NO 1
		C 1

Danfoss 80G8043.02

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Network Topology

The network cable must be EIA485 rated. The cable is connected from controller to controller, and no branches (stars) are allowed on the cable. If the cable length exceeds 1200 meters (1312 yards) a repeater must be inserted. One repeater must be added for every 32 controllers. If the data communication cable runs through an electrically noisy environment which impairs the data signal, one or more repeaters must be added to stabilize the signal. When configuring

Modbus devices on the control bus, the highest device address that can be used is 120 (max 120 Modbus control devices in total). The wires are looped from device to device and must observe polarity. A is connected to A and B is connected to B. The shield must be connected and complete a path from the device, all controllers, any repeaters finally landed on the ground/shield terminal at the AK-SM 800. The shield must not be connected to earth ground except at the AKSM 800. At the AK-SM 800 the shield must be attached to the shield terminal and then extended to an external earth ground. See AK-SM 800 User Guide for system 485 wiring instructions.

The maximum number of MCX-RTU is dependent on which AK-SM 800 is used.

The AK-SM 880 (080Z4008 and 080Z4009) may use a maximum of 45 MCX-RTU controllers. The AK-SM 820 (080Z4004) may use a maximum of 10 MCX-RTU controllers.

The AK-SM 800 User Manual can be found at:

http://food-retail.danfoss.com/knowledge-center/software/ak-sm-800/

Be sure to configure the Modbus repeater AKA 222 (code#084B2240) to the correct baud rate. MCX-RTU baud rate must be set to 38.4 K when used with the AK-SM 800. MCX-RTU cannot be on the same 485 bus with SLVs.

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Sequence of Operation

Cooling Mode

The Controller is in Cooling Mode when the Zone Temperature is above Cool1 Target minus two times the programmed Cool Range. At this point Free Cooling will be active if the Damper and Free Cooling are enabled. The Damper will modulate to maintain the Supply Air or Mixed Air target temperature. Free Cooling is enabled when Zone Enthalpy is above Outdoor Enthalpy and the above conditions are met. Free Cooling will lockout if the Outdoor Enthalpy, Temperature or Relative Humidity are above their specific lockout values.

The Cooling stages will become active when the Zone Temperature is above Cool1 Target minus the Cool Range. Before any cooling stages are activated, the fan must be proofed by either a digital input or analog input to insure the fan is operational. The method of operation depends on the Cooling stages configuration. It is required for the previous stage of Cooling be ON prior to the next stage activating.

If all Cooling stages are configured to use Relay Outputs, then the stages will turn on at Cool Target plus the Range and off at Cool Target minus the Range. Each stage has a Target, PreDelay and PostDelay. PreDelay is the delay period once the conditions have been met for the stage to activate. PostDelay is the period the output will stay on once the conditions have been met for the stage to deactivate.

If any cooling stages are configured to use an Analog Output, the sequence of operation changes. All stages that use an Analog Output must precede stages that use Relay Outputs. In this configuration, the first stage will start when the Zone Temperature reaches the Cool 1 Target minus the Range. The Analog Output will be set to the Min Compr1 Speed. The speed ramps to 100% when the Zone Temperature reaches the Cool 1 Target plus the Range. When Zone Temperature reaches the Cool 2 Target minus the Range the second stage activates, and the first stage reduces to Min Compr1 Speed. If the second stage uses an Analog Output, then the output will use the same value used by Cool Stage 1. If there are more than 2 stages, Min Compr Speed will adjust so the total cooling capacity will equal the maximum capacity of the previous cooling stage. All the Cooling Analog Outputs will always be in sync as they rise.

Fan control during Cooling Mode depends on the type of fan controlled. For Single Speed Fan, the fan will be ON whenever there is a demand for cooling. If the fan is configured for continuous operation, then the fan runs all the time. For Two Speed Fan, the fan will be on high speed whenever there is a demand for cooling. If the fan is configured for continuous operation, the fan will switch to Low Speed with no demand for cooling. If the fan is configured for On Demand, the fan switches off when there is no demand for cooling. For Variable Speed Fan, the fan modulates to maintain the Cooling Supply Air Target with a demand for cooling. If the fan

is configured for continuous operation the fan modulates to the Cool Min Fan Speed with no demand for cooling. If the fan is configured for On Demand, and there is no demand for cooling, the fan either modulate to Cool Min Fan Speed or turns OFF, depending on setting of the Fan Control Demand parameter.

Note: On DOAS units with more than 2 stages of cooling, the first two stages turn ON together. With the balance of the stages turning ON sequentially.

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Heating Mode

The Controller is in Heating Mode when the Zone Temperature is below Cool1 Target minus 2x the Cool Range. Before any heating stages are activated, the fan must be proofed by either a digital input or analog input to insure the fan is operational.

The first type of heating is Heat Reclaim. The first stage of Heat Reclaim will turn on when the Zone Temperature is below Heat Reclaim 1 Target minus the Heat Reclaim Range. The first stage of Heat Reclaim will turn off when the Zone Temperature is above Heat Reclaim 1 Target plus the Heat Reclaim Range. This occurs for each stage of Heat Reclaim. Each stage has their own Target, PreDelay and PostDelay. PreDelay is the delay period once the conditions have been met

for the stage to activate. PostDelay is the period the output will stay on once the conditions have been met for the stage to deactivate. It is required that the previous stage of Heat Reclaim be ON prior to the next stage activating.

The first type of heating is the Aux Heat. The first stage of Aux Heat will turn on when the Zone Temperature is below Aux Heat 1 Target minus Aux Heat Range. The first stage of Aux Heat will turn off when the Zone Temperature is above Aux Heat 1 Target plus Aux Heat Range. This will occur for each stage of Aux Heat. Each stage has its own Target, PreDelay and PostDelay. PreDelay is the period the output delays once the conditions have been met for the stage to activate. PostDelay is the period the output will stay on once the conditions have been met for

the stage to deactivate. It is required that the previous stage of Aux Heat be ON prior to the next stage activating.

Fan control during Heating Mode depends on the type of fan being controlled. For Single Speed Fan, the fan will be on whenever there is a demand for heating. If configured for continuous operation, then the fan will run all the time. For Two Speed Fan, the fan will be on high speed whenever there is a demand for heating. If the fan is configured for continuous operation, the fan switches to Low Speed when there is no demand for heating. If the fan is configured for

On Demand, the fan will switch OFF when there is no demand for heating. For Variable Speed Fan, the fan modulates to maintain the Aux Heat Supply Air Target when there is a demand for heating. If the fan is configured for continuous operation the fan modulates to the Heat Reclaim/ Aux Heat Min Fan Speed with no demand for heating. If the fan is configured for On Demand, and there is no demand for heating the fan either modulates to Heat Reclaim/Aux Heat Min Fan Speed or turns OFF depending on the setting of the Fan Control Demand parameter.

Dehumidification Mode

The Controller is in Dehumidification Mode when the Zone RH or Dewpoint is above Dehumidification 1 Target plus the Dehumidification Range. Before any dehumidification stages are activated, the fan must be proofed by either a digital input or analog input to insure the fan is operational.

If all Cooling stages are configured to use Relay Outputs, then the Dehumidification stages turn on when the Zone Relative Humidity or Zone Dewpoint is above the Dehumidification Target plus the Range and off at Dehumidification Target minus the Range. Each stage has its own Target, PreDelay and PostDelay. PreDelay is the delay period once the conditions have been met for the stage to activate. PostDelay is the period the output stays on once the conditions have been met for the stage to deactivate.

If any of the Cooling stages are configured to use Analog Outputs, then the Dehumidification stages use a modulating capacity method. The Dehumidification Mode is enabled when the Zone RH or Dewpoint is above Dehumidification 1 Target plus the Dehumidification Range.

Once the Dehumidification Mode is enabled the first stage compressor turns on and modulates to maintain the Compressor 1 Target Pressure. Each stage has its own Target and Range used to enable that stage of Dehumidification. If the compressor uses an Analog Output, then the compressor modulates to the compressor target pressure. If the compressor uses a Relay Output, then the compressor is turned ON while the stage is enabled. The Dehumidification PreDelay and PostDelay is only used to determine when the Dehumidification Stage is enabled. It does not control the compressors directly.

Fan control during Dehumidification Mode depends on the type of fan being controlled. For Single Speed Fan, the fans ON whenever there is a demand for dehumidification. If the fan is configured for continuous operation, the fan will run all the time. For Two Speed Fan, the fans on high speed whenever there is a demand for dehumidification. If the fan is configured for continuous operation, the fan switches to Low Speed with no demand for dehumidification. If the fan is configured for On Demand, the fan switches OFF when there is no demand for dehumidificati-

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on. For Variable Speed Fan, the fan will run at Cooling Max Fan Speed until all stages of dehumidification are running at 100% capacity for the time specified in the Max Capacity Period setting. Once this occurs, the fan modulates trying to lower the compressor capacity to 98%. If the fan is configured for continuous operation the fan modulates to the Cool Min Fan Speed with no demand for dehumidification. If the fan is configured for On Demand, and there is no demand for dehumidification, the fan will either modulate to Cool Min Fan Speed or turn OFF depending on the setting of the Fan Control Demand parameter.

CO2 Mode

The CO2 Mode is for health and safety of everyone in the facility. CO2 Mode has priority over all other modes. And there are no lockouts to effect operation.

CO2 control requires an Analog Output to control the damper. The damper activates when the Zone CO2 level reaches CO2 Target minus the CO2 Range. The damper modulates proportionally between the CO2 Target minus the CO2 Range and CO2 Target plus the CO2 Range.

DOAS Mode

DOAS Mode is a combination of all the above modes.

DOAS Mode is controlled by the value for C23 under Setup Options. If set to yes, then the operation is as follows.

Fan Speed is fixed to the value set by parameter FN7 – OvrdFanSpeed(Parameters->Fan)

Outdoor Temperature and Outdoor Relative Humidity are used in place of both the Zone Temperature and Zone Relative Humidity for the Cooling/Heading/Dehumidification modes.

The Damper is set to the DM0(Damper Ovrd Value) value and does not modulate. This value will typically be set to 80%. Note that if this value is less than 100%, and CO2 Mode is calling for the Damper to open more, then the Damper will open to the value requested by the CO2 mode.

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