Factory Packaged Controls
OE377-26-00060
(AAON Part No. V20780)
MODGAS-XWR Controller
Technical Guide
MADE IN USA
YS102530 REV 1
WATTMASTER
CONTROLS
RESET IN
SAT
GND
AUX AIN
GND
STATUS
ALARM
COMM
POWER
ANODE
AUX BIN
HEAT EN
OPTIONS
ALARM
www.aaon.com
OE377-26-00060
MODGAS-XWR
INPUT TERMINALS (TYPE)
GND
AUX. (BI)
HEAT ENABLE (BI)
RESET INPUT (AI)
SAT INPUT (AI)
GND(AI)
AUX. (AI)
GND
WattMaster No:
#SW000055
Rev.: 1A
GND
+24 VAC
I2C
CONNECT
M
MENU
DOWN
AAON No.: V20780
CONTACT RATING
IS 1 AMP MAX
@ 24 VAC
LOW SPEED
COMMON
PROOF OF IGNITION 1
PROOF OF IGNITION 2
GAS VALVE
TERMINALS
E-BUS
CONNECT
UP
RELAY OUTPUT
TERMINALS
FAN
HEAT 1
HEAT 2
GAS VALVE 1
GAS VALVE 2
ENTER
COMMON
PO-IGN1
ANODE
GAS VALVE 1
PO-IGN2
ANODE
GAS VALVE 2
RLY1
RLY2
RLY3
RLY4
TABLE OF CONTENTS
OVERVIEW & FEATURES ..................................................................................................3
INSTALLATION & WIRING .................................................................................................4
Important Wiring Considerations ..............................................................................................................................4
MODGAS-XWR Stand Alone Wiring ........................................................................................................................5
MODGAS-XWR Controller to Main Controller Wiring ..............................................................................................9
INPUTS/OUTPUTS ...........................................................................................................12
OPERATION MODES & STAGING CONFIGURATIONS .....................................................13
LCD DISPLAY SCREENS ..................................................................................................14
TROUBLESHOOTING .......................................................................................................20
LED Diagnostics ....................................................................................................................................................20
Troubleshooting Alarms ................................................................................................................................................22
Temperature Sensor Testing .................................................................................................... ....................................23
APPENDIX A - Supply Air Temperature Sensor Guide ...................................................25
Supply Air Temperature Sensor Installation ...........................................................................................................25
Supply Air Temperature Sensor Wiring Chart and Jumper Settings ......................................................................26
APPENDIX B - MODGAS-XWR Replacement of MODGAS II ............................................27
PART NUMBER CROSS REFERENCE TABLE
PART DESCRIPTION ORION AAON TULSA
MODGAS-XWR Controller OE377-26-00060 V20780
VCM-X Modular E-BUS Controller OE332-23E-VCMX-MOD-A V07150
VCB-X Controller OE335-26B-VCBX V28940
VCC-X Controller OE338-26B-VCCX V42430
12-Relay E-BUS Expansion Module OE358-23E-12R
Supply Air Temperature Sensor OE231 P87140
EBC E-BUS Cables - varying lengths EBC-XXXF N/A
TSDRSC Cables - varying lengths TSDRSC-XXXF N/A
www.aaon.com
R69180
2
WattMaster Controls Inc.
8500 NW River Park Drive · Parkville, MO 64152
Toll Free Phone: 866-918-1100
PH: (816) 505-1100 · FAX: (816) 505-1101 ·
E-mail: mail@wattmaster.com
Visit our web site at www.orioncontrols.com
WattMaster Form: AA-MODGASXWR-TGD-01B
AAON® Manual Part No.: V22330
Copyright April 2015 WattMaster Controls, Inc.
AAON® is a registered trademark of AAON, Inc., Tulsa, OK.
Neither WattMaster Controls, Inc. nor AAON® assumes any
responsibility for errors or omissions in this document.
This document is subject to change without notice.
MODGAS-XWR Technical Guide
OVERVIEW
General Information
Overview
The OE377-26-00060 MODGAS-XWR Controller (AAON Part No.
V20780) is designed to modulate up to two (2) gas valves to maintain
a desired Discharge Air Temperature. The MODGAS-XWR Controller also controls the speed of the induced draft fan to maintain proper
combustion in the heat exchanger. See Figure 1.
The controller can be used as a stand-alone unit or be connected to
a VCM-X E-BUS Controller (OE332-23E-VCMX; AAON Part No.
V07150), VCB-X Controller (OE335-26B-VCBX; AAON Part No.
V28940), VCC-X Controller (OE338-26B-VCCX; AAON Part No.
V42430), or 12 Relay E-BUS Expansion Module (OE358-23E-12R;
AAON Part No. R69180) using a modular cable.
The MODGAS-XWR Controller can be confi gured at the factory for one
(1) modulating valve, two (2) staged modulating valves, or one (1) modulating with multiple fi xed staged valves (stand-alone operation only).
When using the MODGAS-XWR Controller to replace an existing
MODGAS II Controller, see Appendix B, page 27 for details.
MODGAS-XWR CONTROLLER
(OE377-26-00060)
Features
The MODGAS-XWR Controller provides the following:
• Can control two (2) Gas Valves using input from
Proof of Ignition Modules
• Up to four (4) MODGAS-XWR Modules can be daisychained together to control up to eight (8) Modulation Gas
Valves
• Monitors Supply Air Temperature and Supply Air Reset
and modulates gas valves to maintain Setpoint
• Provides active relays to control the Fan and
Heat Stages
• Contains a 2 x 8 LCD character display and 4 buttons
that allow for status display, setpoint changes, and
confi guration changes
NOTE: The MODGAS-XWR Controller contains no user-
serviceable parts. Contact qualifi ed technical personnel
if your MODGAS-XWR Controller is not operating
correctly.
MADE IN USA
YS102530 REV 1
WATTMASTER
CONTROLS
RESET IN
SAT
GND
AUX AIN
GND
STATUS
ALARM
COMM
POWER
ANODE
AUX BIN
HEAT EN
OPTIONS
ALARM
www.aaon.com
OE377-26-00060
MODGAS-XWR
INPUT TERMINALS (TYPE)
GND
AUX. (BI)
HEAT ENABLE (BI)
RESET INPUT (AI)
SAT INPUT (AI)
GND(AI)
AUX. (AI)
GND
WattMaster No:
#SW000055
Rev.: 1A
GND
+24 VAC
I2C
CONNECT
CONTACT RATING
Figure 1: OE377-26-00060 MODGAS-XWR Controller
M
MENU
DOWN
AAON No.: V20780
IS 1 AMP MAX
@ 24 VAC
LOW SPEED
HEAT 1
HEAT 2
COMMON
PROOF OF IGNITION 1
PROOF OF IGNITION 2
GAS VALVE
TERMINALS
E-BUS
CONNECT
UP
RELAY OUTPUT
TERMINALS
FAN
GAS VALVE 1
GAS VALVE 2
ENTER
COMMON
PO-IGN1
ANODE
PO-IGN2
ANODE
RLY1
RLY2
RLY3
RLY4
GAS VALVE 1
GAS VALVE 2
MODGAS-XWR Technical Guide
3
WIRING
Important Wiring Considerations
Important Wiring Considerations
Please read carefully and apply the following information when wiring the
MODGAS-XWR Controller. The MODGAS-XWR Controller
requires the following electrical connections:
1. 18 gauge minimum wire unless otherwise noted
24 VAC power connection with an appropriate VA rating
2.
3. Supply Air Temperature Sensor and Heat Enable must have
24 gauge minimum wire
4. All 24 VAC wiring must be connected so that all ground
wires remain common. Failure to follow this procedure can
result in damage to the module and connected devices
5. All wiring is to be in accordance with local and
national electrical codes and specifi cations
6. Check all wiring leads at the terminal block for tightness.
Be sure that wire strands do not stick out and touch
adjacent terminals. Confi rm that all transducers required for
your system are mounted in the appropriate location and
wired into the correct terminals
WARNING: Do Not Connect Power To VOUT/Ground
Terminal Block!
WARNING: Observe polarity! All boards must be wired
GND-to-GND and 24 VAC-to-VAC. Failure
to observe polarity could result in damage to
the board.
4
MODGAS-XWR Technical Guide
WIRING
Single Modulating Valve No Staging - Stand-Alone Wiring
Single Modulating Valve No Staging Stand-Alone Wiring
This configuration operates as Stand-Alone (Figure 2, below) or
communicating with an AAON Unit Controller (Figure 6, page 9).
If using an MHGRV-X Controller along with the MODGAS-XWR
Controller in Stand-Alone, the SAT Sensor always attaches to the
MODGAS-XWR Controller.
MODGAS-XWR CONTROLLER
Connect SAT
Input to Reheat
Board’s SAT
Input if Applicable.
See Table 7,
Page 26.
0-10VDC
External
Reset Signal
Heat Enable
Signal
(24VAC)
W1
MADE IN USA
YS102530 REV 1
WATTMASTER
CONTROLS
RESET IN
SAT
GND
AUX AIN
GND
STATUS
ALARM
COMM
POWER
ANODE
AUX BIN
HEATEN
OPTIONS
ALARM
www.aaon.com
OE377-26-00060
MODGAS-XWR
INPUT TERMINALS (TYPE)
GND
AUX. (BI)
HEAT ENABLE (BI)
RESET INPUT (AI)
SAT INPUT (AI)
GND(AI)
AUX. (AI)
GND
WattMaster No:
#SW000055
Rev.: 1A
WARNING: Do Not Connect Power To VOUT/Ground
Terminal Block!
(OE377-26-00060)
UP
M
MENU
DOWN
AAON No.: V20780
CONTACT RATING
IS 1 AMP MAX
@ 24 VAC
FAN
LOW SPEED
HEAT 1
HEAT 2
COMMON
PROOF OF IGNITION 1
GAS VALVE 1
PROOF OF IGNITION 2
GAS VALVE
TERMINALS
GND
CONNECT
+24 VAC
I2C
E-BUS
CONNECT
GAS VALVE 2
ENTER
RELAY OUTPUT
TERMINALS
COMMON
PO-IGN1
ANODE
PO-IGN2
ANODE
RLY1
RLY2
RLY3
RLY4
GAS VALVE 1
GAS VALVE 2
Check Your Fan
Relay Wiring (RLY1)
Schematic For
Proper Wiring.
Proof of Ignition
Signal 1 (24 VAC)
Fan Enable
Low Speed Fan
Heat Valve 1
Modulating
Gas Valve 1
See
Table 8, Page 26
For SAT OPTIONS Jumper Settings
Only One Supply Air Temperature Sensor
Can Be Used Per Application.
Figure 2: Single Modulating Valve No Staging Stand-Alone Wiring Diagram
MODGAS-XWR Technical Guide
5
WIRING
Single Modulating Valve & 1 Fixed Heat Stage - Stand-Alone
One Modulating Valve & 1 Fixed Heat
Stage Stand-Alone Wiring
This configuration operates as Stand-Alone (Figure 3, below) or
communicating with an AAON Unit Controller (Figure 7, page 10).
If using an MHGRV-X Controller along with the MODGAS-XWR
Controller, the SAT Sensor always attaches to the MODGAS-XWR
Controller.
The fi xed stage uses the Heat Enable 1 relay to enable it (Figure 3,
below).
MODGAS-XWR CONTROLLER
Connect SAT
Input to Reheat
Board’s SAT
Input if Applicable.
See Table 7,
Page 26.
0-10VDC
External
Reset Signal
Heat Enable
Signal
(24VAC)
W1
-
MADE IN USA
YS102530 REV 1
WATTMASTER
CONTROLS
RESET IN
SAT
GND
AUX AIN
GND
STATUS
ALARM
COMM
POWER
ANODE
AUX BIN
HEATEN
OPTIONS
ALARM
www.aaon.com
OE377-26-00060
MODGAS-XWR
INPUT TERMINALS (TYPE)
GND
AUX. (BI)
HEAT ENABLE (BI)
RESET INPUT (AI)
SAT INPUT (AI)
GND(AI)
AUX. (AI)
GND
WattMaster No:
#SW000055
Rev.: 1A
NOTE: Up to 12 additional fi xed stages can be added by using the
12-Relay E-BUS Expansion Module. (Figure 5, page 8).
WARNING: Do Not Connect Power To VOUT/Ground
Terminal Block!
(OE377-26-00060)
UP
M
MENU
DOWN
AAON No.: V20780
GND
+24 VAC
I2C
CONNECT
CONTACT RATING
IS 1 AMP MAX
@ 24 VAC
GAS VALVE
TERMINALS
RELAY OUTPUT
FAN
LOW SPEED
HEAT 1
HEAT 2
COMMON
PROOF OF IGNITION 1
GAS VALVE 1
PROOF OF IGNITION 2
GAS VALVE 2
E-BUS
CONNECT
ENTER
TERMINALS
COMMON
PO-IGN1
ANODE
PO-IGN2
ANODE
RLY1
RLY2
RLY3
RLY4
GAS VALVE 1
GAS VALVE 2
Check Your Fan
Relay Wiring (RLY1)
Schematic For
Proper Wiring.
Fan Enable
Low Speed Fan
Heat Valve 1
Fixed Heat Stage
Proof of Ignition
Signal 1 (24 VAC)
Modulating
Gas Valve 1
See
Table 8, Page 26
For SAT OPTIONS Jumper Settings
Only One Supply Air Temperature Sensor
Can Be Used Per Application.
Figure 3: Single Modulating Valve & 1 Fixed Stage - Stand-Alone
6
EBC-E-BUS Cable
Can Connect To
12 Relay E-BUS
Expansion
Port
MODGAS-XWR Technical Guide
WIRING
Two Modulating Valves Staged - Stand-Alone Wiring
Two Modulating Valves Staged Stand-Alone Wiring
This configuration operates as Stand-Alone (Figure 4, below) or
communicating with an AAON Unit Controller (Figure 8, page 11).
If using an MHGRV-X Controller along with the MODGAS-XWR
Controller in Stand-Alone, the SAT Sensor always attaches to the
MODGAS-XWR Controller.
MODGAS-XWR CONTROLLER
Connect SAT
Input to Reheat
Board’s SAT
Input if Applicable.
See Table 7,
Page 26.
0-10VDC
External
Reset Signal
Heat Enable
Signal
(24VAC)
W1
MADE IN USA
YS102530 REV 1
WATTMASTER
CONTROLS
RESET IN
SAT
GND
AUX AIN
GND
STATUS
ALARM
COMM
POWER
ANODE
AUX BIN
HEATEN
OPTIONS
ALARM
www.aaon.com
OE377-26-00060
MODGAS-XWR
INPUT TERMINALS (TYPE)
GND
AUX. (BI)
HEAT ENABLE (BI)
RESET INPUT (AI)
SAT INPUT (AI)
GND(AI)
AUX. (AI)
GND
WattMaster No:
#SW000055
Rev.: 1A
NOTE: Up to 12 fi xed stages can be added by using the 12-Relay
E-BUS Expansion Module. (Figure 5, page 8).
WARNING: Do Not Connect Power To VOUT/Ground
Terminal Block!
(OE377-26-00060)
UP
M
MENU
DOWN
AAON No.: V20780
CONTACT RATING
IS 1 AMP MAX
@ 24 VAC
FAN
LOW SPEED
HEAT 1
HEAT 2
COMMON
PROOF OF IGNITION 1
GAS VALVE 1
PROOF OF IGNITION 2
GAS VALVE
TERMINALS
GND
CONNECT
+24 VAC
I2C
E-BUS
CONNECT
GAS VALVE 2
ENTER
RELAY OUTPUT
TERMINALS
COMMON
PO-IGN1
ANODE
PO-IGN2
ANODE
RLY1
RLY2
RLY3
RLY4
GAS VALVE 1
GAS VALVE 2
Check Your Fan
Relay Wiring (RLY1)
Schematic For
Proper Wiring.
Fan Enable
Low Speed Fan
Heat Valve 1
Heat Valve 2
Proof of Ignition
Signal 1 (24 VAC)
Modulating
Gas Valve 1
Proof of Ignition
Signal 2 (24 VAC)
Modulating
Gas Valve 2
See
Table 8, Page 26
For SAT OPTIONS Jumper Settings
Only One Supply Air Temperature Sensor
Can Be Used Per Application.
Figure 4: Two Modulating Valves Staged Stand-Alone Wiring Diagram
MODGAS-XWR Technical Guide
EBC-E-BUS Cable
Can Connect To
12 Relay E-BUS
Expansion
Port
7
WIRING
12-Relay E-BUS Expansion Module - Stand Alone
One Modulating Valve with 1 Fixed
Stage or Two Modulating Valves Stand-Alone Wiring, Continued
If communication is lost to the 12-Relay E-BUS Expansion Module,
the 12-Relay E-BUS Expansion Module will turn off its relays and the
MODGAS-XWR Controller will alarm and fall back to using only its
onboard stages. If communications is restored, the MODGAS-XWR
Controller will begin staging up if needed.
The 12-Relay E-BUS Expansion Module is only used with Single
Modulating Valve One Fixed Stage Stand-Alone (Figure 3, page 6) or
Two Modulating V alves Stand-Alone (Figur e 4, page 7) confi gurations.
See Figure 5, below.
WARNING!!
Observe Polarity! All boards must be wired with GND-to-GND and 24VAC-to-24VAC. Failure to observe polarity will result in damage to
one or more of the boards. Expansion Modules must be wired in such a way that the expansion modules and the controller are always
powered together. Loss of power to the expansion module will cause the controller to become inoperative until power is restored to the
expansion module.
12-Relay E-BUS
Note:
All Relay Outputs Are Normally Open
And Rated For 24 VAC Power Only.
1 Amp Maximum Load.
R1
Fixed Heat Stage 3
R2
Fixed Heat Stage 4
R3
Fixed Heat Stage 5
R4
Fixed Heat Stage 6
Expansion Module
COM
RLY1
RLY2
RLY3
RLY4
RLY-COM
RLY1
RLY2
RLY3
RLY4
MADE IN USA
RLY-COM
RLY9
RLY10
RLY11
RLY12
COM
RLY9
RLY10
RLY11
RLY12
Fixed Heat Stage 11
Fixed Heat Stage 12
Fixed Heat Stage 13
Fixed Heat Stage 14
R9
R10
R11
R12
R5
Fixed Heat Stage 7
R6
Fixed Heat Stage 8
R7
Fixed Heat Stage 9
R8
Fixed Heat Stage 10
COM
RLY5
RLY6
RLY7
RLY8
EBC E-BUS Cable
Connect To MODGAS-XWR Controller
RLY-COM
RLY5
RLY6
RLY7
RLY8
RELAY
EXPANSION BOARD
YS102324 REV 2
GND
24VAC
GND
24 VAC
15 VA Minimum
Power Required
GND
24 VAC
Figure 5: Stand-Alone Up to 12 Additional Stages of Fixed Heat - 12-Relay E-BUS Expansion Module
8
MODGAS-XWR Technical Guide
WIRING
Single Modulating Valve No Staging - Communicating Wiring
Single Modulating Valve No Staging Communicating Wiring
This confi guration operates as Stand-Alone (Figure 2, page 5) or
communicating with an AAON Unit Controller (Figure 6, below).
For connection to a VCB-X Controller or VCB-X Expansion Module,
use an E-BUS Cable connecting to the appropriate E-BUS ports on
those controllers.
Connect
Only One Supply Air Temperature Sensor
Supply Air Temperature
to AI2 & GND
Sensor
On Main Controller
Mount In Supply
Air Duct
Supply
Air Temperature
Sensor
The SAT OPTIONS Jumper Setting
Should Be Set to 1.
See For Settings.
Table 9, Page 26
Can Be Used Per Application.
MADE IN USA
YS102530 REV 1
WATTMASTER
CONTROLS
RESET IN
SAT
GND
AUX AIN
GND
STATUS
ALARM
COMM
POWER
ANODE
MODGAS-XWR CONTROLLER
ALARM
AUX BIN
HEATEN
OPTIONS
www.aaon.com
OE377-26-00060
MODGAS-XWR
INPUT TERMINALS (TYPE)
GND
AUX. (BI)
HEAT ENABLE (BI)
RESET INPUT (AI)
SAT INPUT (AI)
GND(AI)
AUX. (AI)
GND
WattMaster No:
#SW000055
Rev.: 1A
For all other controllers, including VCM-X or Expansion Modules, use
an I2C Cable connecting to the appropriate I2C ports on those controllers.
WARNING: Do Not Connect Power To VOUT/Ground
Terminal Block!
NOTE: If additional fi xed stages are required, these should be
confi gured and wired to the AAON Unit Controller’s
relays.
(OE377-26-00060)
UP
M
MENU
DOWN
AAON No.: V20780
GND
+24 VAC
I2C
CONNECT
CONTACT RATING
IS 1 AMP MAX
@ 24 VAC
GAS VALVE
TERMINALS
RELAY OUTPUT
FAN
LOW SPEED
HEAT 1
HEAT 2
COMMON
PROOF OF IGNITION 1
GAS VALVE 1
PROOF OF IGNITION 2
GAS VALVE 2
E-BUS
CONNECT
ENTER
TERMINALS
COMMON
PO-IGN1
ANODE
PO-IGN2
ANODE
RLY1
RLY2
RLY3
RLY4
GAS VALVE 1
GAS VALVE 2
Check Your Fan
Relay Wiring (RLY1)
Schematic For
Proper Wiring.
Fan Enable
Low Speed Fan
Heat Valve 1
Proof of Ignition
Signal 1 (24 VAC)
Modulating
Gas Valve 1
Modular Cable Connects To
VCM-X E-BUS Controller’s
Expansion Port
Figure 6: Single Modulating Valve No Staging Communicating Wiring Diagram
MODGAS-XWR Technical Guide
EBC E-BUS Cable
Connects To
VCB-X Controller’s
Expansion
Port
9
WIRING
Single Modulating Valve & 1 Fixed Stage - Communicating Wiring
Single Modulating Valve & 1 Fixed
Stage - Communicating Wiring
This confi guration operates as Stand-Alone (Figure 3, page 6) or
communicating with an AAON Unit Controller (Figure 7, below).
For connection to a VCB-X Controller or VCB-X Expansion Module,
use an E-BUS Cable connecting to the appropriate E-BUS ports on
those controllers.
Connect
Supply Air Temperature
to AI2 & GND
Sensor
On Main Controller
Mount In Supply
Air Duct
Supply
Air Temperature
Sensor
The SAT OPTIONS Jumper Setting
Should Be Set to 1.
See For Settings.
Table 9, Page 26
Only One Supply Air Temperature Sensor
Can Be Used Per Application.
MADE IN USA
YS102530 REV 1
WATTMASTER
CONTROLS
RESET IN
SAT
GND
AUX AIN
GND
STATUS
ALARM
COMM
POWER
ANODE
AUX BIN
HEATEN
OPTIONS
MODGAS-XWR CONTROLLER
ALARM
www.aaon.com
OE377-26-00060
MODGAS-XWR
INPUT TERMINALS (TYPE)
GND
AUX. (BI)
HEAT ENABLE (BI)
RESET INPUT (AI)
SAT INPUT (AI)
GND(AI)
AUX. (AI)
GND
WattMaster No:
#SW000055
Rev.: 1A
For all other controllers, including VCM-X or Expansion Modules, use
an I2C Cable connecting to the appropriate I2C ports on those controllers.
WARNING: Do Not Connect Power To VOUT/Ground
Terminal Block!
(OE377-26-00060)
UP
M
MENU
DOWN
AAON No.: V20780
GND
+24 VAC
I2C
CONNECT
CONTACT RATING
IS 1 AMP MAX
@ 24 VAC
GAS VALVE
TERMINALS
RELAY OUTPUT
FAN
LOW SPEED
HEAT 1
HEAT 2
COMMON
PROOF OF IGNITION 1
GAS VALVE 1
PROOF OF IGNITION 2
GAS VALVE 2
E-BUS
CONNECT
ENTER
TERMINALS
COMMON
PO-IGN1
ANODE
PO-IGN2
ANODE
RLY1
RLY2
RLY3
RLY4
GAS VALVE 1
GAS VALVE 2
Check Your Fan
Relay Wiring (RLY1)
Schematic For
Proper Wiring.
Fan Enable
Low Speed Fan
Heat Valve 1
Fixed Heat Stage
Proof of Ignition
Signal 1 (24 VAC)
Modulating
Gas Valve 1
EBC E-BUS Cable
VCB-X Controller’s
Modular Cable Connects To
VCM-X E-BUS Controller’s
Expansion Port
Figure 7: Single Modulating Valve & 1 Fixed Stage Communicating Wiring Diagram
10
MODGAS-XWR Technical Guide
Connects To
Expansion
Port
WIRING
Two Modulating Valves Staged - Communicating Wiring
Two Modulating Valves Staged Communicating Wiring
This confi guration operates as Stand-Alone (Figure 4, page 7) or
communicating with an AAON Unit Controller (Figure 8, below).
For connection to a VCB-X Controller or VCB-X Expansion Module,
use an E-BUS Cable connecting to the appropriate E-BUS ports on
those controllers.
Connect
Only One Supply Air Temperature Sensor
Supply Air Temperature
to AI2 & GND
Sensor
On Main Controller
Mount In Supply
Air Duct
Supply
Air Temperature
Sensor
The SAT OPTIONS Jumper Setting
Should Be Set to 1.
See For Settings.
Table 9, Page 26
Can Be Used Per Application.
MADE IN USA
YS102530 REV 1
WATTMASTER
CONTROLS
RESET IN
SAT
GND
AUX AIN
GND
STATUS
ALARM
COMM
POWER
ANODE
MODGAS-XWR CONTROLLER
ALARM
AUX BIN
HEATEN
OPTIONS
www.aaon.com
OE377-26-00060
MODGAS-XWR
INPUT TERMINALS (TYPE)
GND
AUX. (BI)
HEAT ENABLE (BI)
RESET INPUT (AI)
SAT INPUT (AI)
GND(AI)
AUX. (AI)
GND
WattMaster No:
#SW000055
Rev.: 1A
For all other controllers, including VCM-X or Expansion Modules, use
an I2C Cable connecting to the appropriate I2C ports on those controllers.
WARNING: Do Not Connect Power To VOUT/Ground
Terminal Block!
(OE377-26-00060)
UP
M
MENU
DOWN
AAON No.: V20780
GND
+24 VAC
I2C
CONNECT
CONTACT RATING
IS 1 AMP MAX
@ 24 VAC
GAS VALVE
TERMINALS
RELAY OUTPUT
FAN
LOW SPEED
HEAT 1
HEAT 2
COMMON
PROOF OF IGNITION 1
GAS VALVE 1
PROOF OF IGNITION 2
GAS VALVE 2
E-BUS
CONNECT
ENTER
TERMINALS
COMMON
PO-IGN1
ANODE
PO-IGN2
ANODE
RLY1
RLY2
RLY3
RLY4
GAS VALVE 1
GAS VALVE 2
Check Your Fan
Relay Wiring (RLY1)
Schematic For
Proper Wiring.
Fan Enable
Low Speed Fan
Heat Valve 1
Heat Valve 2
Proof of Ignition
Signal 1 (24 VAC)
Modulating
Gas Valve 1
Proof of Ignition
Signal 2 (24 VAC)
Modulating
Gas Valve 2
Modular Cable Connects To
VCM-X E-BUS or RNZ Controller’s
Figure 8: Two Modulating Valves Staged Communicating Wiring Diagram
MODGAS-XWR Technical Guide
Expansion Port
EBC E-BUS Cable
Connects To
VCB-X Controller’s
Expansion
Port
11
INPUTS & OUTPUTS
Inputs and Outputs
Zone
Zone
I/O Map
The following inputs and outputs are available on the MODGAS-XWR
Controller. See Table 1 below to reference the Input/Output Map.
Analog Inputs
1 Reset Signal (RST IN)
2 Supply Temperature (SAT)
3 (AUX AIN) - Not Used
Binary Inputs
1 (AUX BIN) - Not Used
2 Heat Enable (HEAT EN)
3 Proof of Ignition 1 (PO-IGN1)
4 Proof of Ignition 2 (PO-IGN2)
Communicating Outputs
1 Gas Valve 1
2 Gas Valve 2
Relays
1 Fan (RLY1)
2 Low Speed Fan (RLY2)
3 Heat 1 (RLY3)
4 Heat 2 (RLY4)
Binary Inputs
Heat Enable Contact (HEAT EN)
This input is only required when the controller is used in stand-alone
operation; it is not required when used as an expansion board to other
unit controllers. The Heat Enable input is activated by a 24VAC signal
supplied from a building automation system to enable the MODGASXWR Controller. The controller will not operate without 24VAC being
applied to this input terminal when used in a stand-alone confi guration.
Proof of Ignition 1 (PO-IGN1)
The Proof of Ignition input is activated by a 24VAC signal supplied
from the Ignition Module to enable the modulating Gas Valve 1. If the
fl ame does not ignite, the Ignition Module will turn off this enable.
The MODGAS-XWR Controller will then turn on the “No Proof of
Flame” alarm.
Proof of Ignition 2 (PO-IGN2)
The Proof of Ignition input is activated by a 24VAC signal supplied
from the Ignition Module to enable the modulating Gas Valve 2. If the
fl ame does not ignite, the Ignition Module will turn off this enable.
The MODGAS-XWR Controller will then turn on the “No Proof of
Flame” alarm.
Communicating Outputs
Gas Valve Output 1
This communicating output will control the modulating gas valve. It
can detect if the valve is connected and can verify the valve position.
Table 1: MODGAS-XWR Controller Inputs &
Outputs
Analog Inputs
Reset Input (RST IN)
Used only in stand-alone operation. The Discharge T emperature Setpoint
can be reset by supplying a 0-10 VDC signal to the RST IN low voltage
terminal block. This reset signal is optional and need only be used if you
require resetting of the discharge air temperature.
Supply Air Temperature Sensor (SAT)
Used only in stand-alone operation. The Supply Air Temperature Sensor is the control source. This sensor has to be installed for the unit to
operate. The Supply Air Sensor is located in the discharge air stream
and monitors discharge air temperature to maintain the discharge air
temperature setpoint.
Gas Valve Output 2
This communicating output will control the modulating gas valve. It
can detect if the valve is connected and can verify the valve position.
Relay Outputs
Relay #1 - Fan Enable
This relay works in conjunction with the Low Speed Fan Relay to control
the speed of the induced draft blower motor. When the MODGAS-XWR
Controller has heat enabled, this relay closes to bring the induced draft
blower on at high speed. The controller will activate the Low Speed
Fan Relay to reduce the induced draft blower speed as the gas valve
modulates closed.
Relay #2 - Low Speed Fan
Depending on the gas valve position, this relay will close to switch the
induced draft blower to low speed. The controller automatically switches
the blower to low speed as the gas valve modulates closed in order to
maintain proper fuel to air ratios.
Relay #3 - Heat 1
Once the MODGAS-XWR Controller brings on heat, Heat 1 Relay is
the fi rst stage of heat.
Relay #4 - Heat 2
Once the MODGAS-XWR Controller brings on heat, Heat 2 Relay is
the second stage of heat if the MODGAS-XWR is confi gured for two
stages of heat.
12
MODGAS-XWR Technical Guide
OPERATION MODES & STAGING CONFIGURATIONS
Operation Modes & Staging Confi gurations
Operation Modes
The MODGAS-XWR Controller can be used stand-alone or connected
to a Main Controller using a modular cable.
Stand Alone Mode
When used in a stand-alone application (not connected to a Main Controller via a modular cable), the MODGAS-XWR Controller will modulate
the gas valve(s) to maintain the DISCHARGE setpoint confi gured on
the MODGAS-XWR Controller LCD display. The MODGAS-XWR
Controller is activated by a 24VAC signal to the HEAT EN input.
The following describes the setpoints available in stand-alone mode for
adjustment using the LCD display on the MODGAS-XWR Controller:
• Supply Air Temperature Setpoint
• Supply Air Reset Temperature Setpoint
Communicating Mode
When the MODGAS-XWR Controller is connected to a Main Controller
via a modular cable, the necessary information will be passed between
the MODGAS-XWR and the Main Controller to properly operate in
the Heating Mode.
If the communication is interrupted between the MODGAS-XWR Controller and the Main Controller, both boards will show an alarm. When
communication is restored, the alarms will go away.
In this confi guration, the Supply Air Temperature Setpoint is set using
the Main Controller and the Supply Air Temperature Reset (if used) is
calculated by the Main Controller. The Supply Air Temperature is sent
to the MODGAS-XWR from the Main Controller.
MODGAS-XWR Staging Confi gurations
The MODGAS-XWR can be confi gured for various Staged Heat con-
fi gurations. These confi gurations can be used in conjunction with the
VCM-X Controller, VCB-X Controller , or 12 Relay Expansion Module.
MODGAS-XWR Stand-Alone Confi guration
In the confi guration screens, select the total Stages as the number of Heat
Stages installed in the unit. This is the number of Fixed and Modulating
Stages combined. Next, select the total Modulating Stages installed in
the unit (White Rodgers valves).
The options for Stand-Alone operation without additional boards are
(1) One modulating, (2) Two modulating, and (3) One modulating and
one fi xed.
MODGAS-XWR Stand-Alone with 12-Relay
E-BUS Expansion Module
If the total number of heat stages exceeds two in a stand-alone operation, then a 12 Relay Expansion Module is needed for proper control.
In the confi guration screens, select the total stages as the number of heat
stages installed in the unit. This is the number of fi xed and modulating
stages combined. There can be up to 14 total stages in this confi gura-
tion. Next, select the total modulating stages installed in the unit (White
Rodgers valves).
The options for stand-alone with 12 relay expansion are (1) One modulating with up to 13 fi xed stages and (2) Two modulating with up to 12
fi xed stages.
In order for the MODGAS-XWR to communicate properly to the 12
Relay Expansion Module, “S/A MODE” needs to be confi gured to
“FORCED”. This confi guration will make the MODGAS-XWR initi-
ate communications with the 12 Relay Expansion Module through the
E-BUS cable.
MODGAS-XWR Communicating with AAON
Unit Controller
If the unit is installed with a main control board, then it needs to be
connected to the MODGAS-XWR via an I2C or E-BUS Expansion
cable. In the confi guration screens, select the total onboard stages as
the number of heat stages connected to the MODGAS-XWR. This is
the number of fi xed and modulating stages combined. Next, select the
total onboard modulating stages installed in the unit (White Rodgers
valves). Additional fi xed stages of heat will be confi gured on the main
control board. Confi gure the fi rst stage of heat on the main control board
as the combined stages of heat connected to the MODGAS-XWR. If
more stages of heat are needed besides the MODGAS-XWR and the
main control board’s confi gurable relays, a 12 relay expansion or an
expansion board can be connected and heat stages can be confi gured
from the main control board.
The confi gurable options on the MODGAS-XWR for this setup are
(1) One modulating, (2) Two modulating, and (3) One modulating and
one fi xed.
The status screen displaying the stage status will show the current heat
stage of all heat stages on the unit. For example, if two stages are active
on the MODGAS-XWR and two stages are active on the main control
board, the current heat stage displayed with show HEAT STAGE 4.
MODGAS-XWR Technical Guide
13
LCD DISPLAY SCREENS
Navigation Keys
LCD Display Screen & Navigation
Keys
The MODGAS-XWR Controller allows you to make confi guration
changes, view status, change setpoints, create force modes, and perform
diagnostics using the keypad next to the LCD display. See Figur e 9 and
refer to Table 2 for descriptions.
Figure 9: LCD Display and Navigation Keys
Main Screens Map
Refer to the following map when navigating through the LCD Main
Screens. The fi rst screen is an initialization screen. To scroll through
the rest of the screens, press the
Press to scroll through MODGAS Screens.
Press to go to STATUS Screens.
Press to scroll through STATUS Screens.
<MENU> button.
MODGAS
STARTUP!
MODGAS
STEPPER
STATUS
SCREEN
NAVIGATION
KEY
MENU
UP
DOWN
ENTER
Use the MENU key to navigate through the
Main Menu Screens.
Use this key to adjust setpoints and change
confi gurations. This key is also used to turn
Valve Force Mode on.
Use this key to adjust setpoints and change
confi gurations. This key is also used to turn
Valve Force Mode off.
Use the Enter key to move through screens
within Main Menu categories. Also, use this
key to save setpoints and confi guration
changes.
KEY FUNCTION
Table 2: Navigation Key Functions
Press to go to ALARMS Screens.
ALARMS
Press to go to SETPOINT Screens.
SETPOINT
Press to scroll through SETPOINT Screens.
Press to go to FORCE Screens.
FORCE
VALVES
Press to scroll through FORCE Screens.
14
MODGAS-XWR Technical Guide
LCD DISPLAY SCREENS
Main Screens Map and MODGAS Screens
Protected Screens Map
Refer to the following map when navigating through the LCD Protected
Screens. From the MODGAS STEPPER Screen, press the
twice until you get to the SOFTWARE Screen. Then hold the <UP>
button for 5 seconds. T o scroll through the rest of the screens, press the
<MENU> button.
MODGAS
STEPPER
S/A MODE
SOFTWARE
1060 V.XXX
<ENTER>
Main MODGAS Screens
Refer to the following map when navigating through the Main Screens.
From the MODGAS Stepper Screen, press
the screens.
MODGAS
STEPPER
S/A or COMM
MODE
In Stand-Alone Mode, the screen will only display S/A MODE.
In Communications Mode, the screen will display COMM MODE and the
items below will scroll through the screen:
1. Number of good packets being received. This will roll over after 9999.
Example: +XXXX
2. Number of checksum errors. This will stop at 9999. Example: C-XXXX
3. Number of packet length errors. This will stop at 9999 until power is
cycled. Example: P-XXXX
<ENTER> to scroll through
Hold for 5 seconds.
CONFIG
DIAGNSTC
ENTER TO
EXIT
SOFTWARE
1060 V.XXX
CURRENT SOFTWARE VERSION
You can access the protected screens from this screen by holding the
<UP> button for 5 seconds.
ADDRESS
1 (138)
CURRENT BOARD ADDRESS
Number in parentheses is E-BUS address.
# STAGES
T=2 M=2
MODGAS-XWR Technical Guide
NUMBER OF STAGES CONFIGURED
T = Total stages fi xed and modulating
M = Total modulating stages
15
LCD DISPLAY SCREENS
Status Screens
Status Screens
Refer to the following map when navigating through the Status Screens.
From the ST A TUS Screen, press
Status Screens shown below will scroll automatically if LCD display is
left on this screen for 20 seconds.
This screen displays the current mode of operation of the MODGASXWR Controller. The mode options are:
OFF: This mode will display when there is no call for heat and heating
has been disabled.
<ENTER> to scroll through the screens.
STATUS
MODE
HEAT
MODE
VALVE 1
100%
VALVE 1 POSITION
0 to 100 percent or Closed
VALVE 2
100%
VALVE 2 POSITION
0 to 100 percent or Closed
SA TEMP
XX.X
IGNITION: Each time Heat is activated, the unit will fi rst go into Ignition
Mode. During this mode, the unit will remain at maximum fi re. The unit
will leave this mode once proof of fi re has been established. Proof of fi re
is established when the SAT rises 5 degrees.
HEAT: After Ignition Mode, the unit will enter the Heat Mode and will
begin to modulate the gas valve to maintain the Heating Supply Air Setpoint (SAT). Once the call for heat goes away, the unit will leave the
Heat Mode.
CUTOFF: The Cutoff Mode occurs if the SAT rises above 200˚F. During
Cutoff Mode, the Heat will be disabled for a fi xed delay period. If the SAT
falls below 200˚F and the delay period has expired, the unit will re-enter
the Heat Mode.
FORCE: The Force Mode occurs when Force Mode is manually turned
on in the Force Mode screens. When you turn the Force Mode back off
or after 1 hour has elapsed, the valve will reinitialize to zero.
SAT FAIL: The SAT FAIL Mode occurs if the Supply Air Temperature
sensor has been disconnected for more than 60 seconds. During SAT
Fail Mode, the Heat will be disabled until the Sensor is reconnected or
detected.
SUPPL Y AIR TEMPERA TURE
40ºF to 150ºF or 4ºC to 65ºC.
If no sensor is detected, screen will display “NO SENSR”
ACTIV SP
XX.X
ACTIVE SUPPLY AIR SETPOINT
Calculated from SAT Setpoint and Reset Setpoint in stand-alone mode.
In communicating mode, the Main Controller sends the setpoint.
The SAT Setpoint is set by the LCD Display in stand-alone mode and is
set by the Main Controller in communicating mode.
16
MODGAS-XWR Technical Guide
LCD DISPLAY SCREENS
Alarm & Setpoint Screens
Alarm Screens
Refer to the following map when viewing Alarm Screens. These screens
will display automatically when alarms are present. For more information, see pages 20-22.
ALARMS
ALARMS
The alarms are as follows:
NO ALARMS: This will be shown if there are no current alarms.
V1 NOT DETECTED: Gas Valve 1 is not detected.
V2 NOT DETECTED: Gas Valve 2 is not detected.
V1 NO PROOF OF FLAME: No Proof of Flame Ignition Module input
is detected..
V2 NO PROOF OF FLAME: No Proof of Flame Ignition Module input
is detected.
SAT CUTOFF: This indicates a Supply Air Temperature Cutoff Alarm
condition which is activated if the SAT has risen above 200ºF. The alarm
will go away if after a fi xed delay period the SAT has dropped below
200ºF.
SAT FAILURE: The Supply Air Temperature sensor has been discon-
nected for more than 60 seconds. This alarm will be disabled when the
sensor is reconnected.
COMM T/O ERROR: Communications have been lost with the main
controller. This alarm will disable when communications resume.
Setpoint Screens
Refer to the following map when navigating through the Setpoint Screens. From the SETPOINT Screen, press
scroll through the screens and change setpoints. Use the <UP>
and <DOWN> arrow keys to change your selections. Then press
<ENTER> to save the new setpoint.
WARNING: The <ENTER> key must be pressed after
changing setpoints for your entries to be saved
for subsequent power-ups.
NOTE: When the MODGAS-XWR is operating in Communi-
cations Mode, these setpoints screens will not appear
on the LCD display because they are controlled by the
Main Controller.
SETPOINT
SAT SP
40-150°F
4-65°C
HEATING SUPPLY AIR TEMPERATURE SETPOINT
This is the target temperature while the heating is enabled. If you are
using the reset signal, this is the setpoint it will calculate to at zero volts.
The Setpoint Screen will display only in stand-alone mode.
<ENTER> to
MODGAS-XWR Technical Guide
Minimum Default Maximum
40°F
4°C
120°F
49°C
150°F
65°C
RESET SP
40-150°F
4-65°C
RESET HEATING SUPPLY AIR SETPOINT
This is maximum temperature at which the Supply Air Temperature will
reset to. The Setpoint Screen will display only in stand-alone mode.
Minimum Default Maximum
40°F
4°C
120°F
49°C
150°F
65°C
17
LCD DISPLAY SCREENS
Force Valve & Confi guration Screens
Force Valve Screens
Refer to the following map when navigating through the Force Valve
Screens. From the FORCE VALVE Screen, press
V1 and V2 FORCE ON/OFF screens, press the <UP> arrow key to
turn the FORCE MODE on and press the <DOWN> arrow key to turn
the FORCE MODE off. Use the <UP> and <DOWN> arrow keys to
increase and decrease the percentage.
FORCE
VALVES
V1 FORCE
ON/OFF
Press the <UP> button to turn the Force Mode on. Press the <DOWN>
button to turn the Force Mode off.
FORCE V1
X%
FORCE VALVE 1 PERCENTAGE
This screen only appears when Valve 1 Force is on.
Press the <UP> button to increase the percentage. Press the <DOWN>
button to decrease the percentage.
<ENTER>. At the
FORCE V2
X%
FORCE VALVE 2 PERCENTAGE
This screen only appears when Valve 2 Force is on.
Press the <UP> button to increase the percentage. Press the <DOWN>
button to decrease the percentage.
NOTE: When you turn the Force Mode back off or after 1 hour has
elapsed, the valve will reinitialize to zero.
This screen below will appear when the Force Mode times out after 1
hour.
FORCE
TIMEOUT
FORCE MODE TIME OUT
Confi guration Screens
Refer to the following map when navigating through the Confi guration
Screens. From the CONFIG Screen, press <ENTER> to scroll through
the screens and change setpoints. Use the <UP> and <DOWN> arrow
keys to change your selections. Press <ENTER> to save any changes.
CONFIG
NOTE: When you turn the Force Mode back off or after 1 hour has
elapsed, the valve will reinitialize to zero.
V2 FORCE
ON/OFF
Press the <UP> button to turn the Force Mode on. Press the <DOWN>
button to turn the Force Mode off.
18
# STAGES
1 TO 15
NUMBER OF TOTAL STAGES
Range is 1 to 15. Default is 2.
# MOD STG
1 OR 2
NUMBER OF MODULATING STAGES
Range is 1 or 2. Default is 2.
MODGAS-XWR Technical Guide
LCD DISPLAY SCREENS
Confi guration & Diagnostic Screens
ADDRESS
1 TO 4
CURRENT ADDRESS OF THE BOARD
The address is only used in communicating mode. Default = 1
STG UP
DLY
1 TO 10
STAGE UP DELAY
Range is 1 to 10 minutes. Default is 3.
STG DOWN
DLY
1 TO 10
STAGE DOWN DELAY
Range is 1 or 10 minutes. Default is 1.
Diagnostic Screens
Refer to the following map when navigating through the Diagnostic
Screens. From the DIAGNSTC Screen, press
through the screens.
DIAGNSTC
WDOG CNT
#
WATCH DOG TIMER
Displays the number of times the board has been reset due to
watchdog timer overfl ow.
PWER CNT
#
<ENTER> to scroll
TMPSCALE
FAHRENHT
TEMPERATURE SCALE
Fahrenheit (default) or Celsius.
This setting is used only in stand-alone mode.
S/A MODE
AUTO DETC or
LOCKED
STAND ALONE MODE
Auto-detect or Locked. Default is Auto-detect.
POWER LOSS COUNT
Displays the number of times the board has been reset
due to power loss.
VLV1 ERR
#
VALVE 1 COMMUNICATION
Displays the number of received PWM communication error signals
from Valve 1. Not necessarily failed communications.
VLV2 ERR
#
VALVE 2 COMMUNICATION
Displays the number of received PWM communication error signals
from Valve 2. Not necessarily failed communications.
MODGAS-XWR Technical Guide
19
TROUBLESHOOTING
LED Diagnostics
LED Diagnostics
The MODGAS-XWR Controller is equipped with LEDs that can be
used to verify operation and perform troubleshooting. There are LEDs
for communication, operation modes, and diagnostic codes. The module
has 14 LEDs—12 used for operation & status, and 2 used for alarms.
See Figure 10 for the LED locations. The LEDs associated with these
inputs and outputs allow you to see what is active without using a voltmeter. The LEDs and their uses are as follows:
Operation LEDs
POWER - This green LED will light up to indicate that 24 VAC power
has been applied to the controller.
STATUS - This green LED will light up and blink the board address at
startup. It will then blink every 10 seconds according to what mode the
controller is in. See Table 3.
No. of
Blinks
1 Off Mode
2 Heating Mode (Heat Enable
Signal and No Alarms)
3 SAT Fail Mode
4 SAT Cutoff Mode
Table 3: STATUS LED Blink Codes
Diagnostic LEDs
ALARM - This red LED located on the MODGAS-X Controller’s cover
above the LCD display will light up to indicate an alarm. The type of
alarm(s) will be shown on the LCD display. The ALARM LED also
blinks when the expansion valve is initializing at startup.
The ALARM LED on the MODGAS-X board will blink an alarm code
every 10 seconds when an alarm(s) occurs. The highest priority failure
code will be indicated fi rst. You must correct the highest priority alarm
before other problems will be indicated. See Table 4.
STATUS LED
Communication LED
COMM - This yellow LED will light up and blink when communications are detected.
Relay LEDs
RLY1 - This green LED will light up and stay lit as long as the Fan
relay is active.
RLY2 - This green LED will light up and stay lit as long as the Low
Speed Fan relay is active.
RLY3 - This green LED will light up and stay lit as long as the Heat
Enable 1 relay is active.
RLY4 - This green LED will light up and stay lit as long as the Heat
Enable 2 relay is active.
Binary Input LEDs
AUX BIN - Not Used.
HEAT EN - This green LED will light up when Heat Enable signal is
activated.
PO-IGN1 - This green LED will light up when the Proof of Flame input
from the fi rst Ignition Module is enabled.
PO-IGN2 - This green LED will light up when the Proof of Flame input
from the second Ignition Module is enabled.
Analog Output LEDs
GAS VALVE 1 - This green LED will blink when Gas Valve 1 is
modulating or commanded to modulate. LED will stay solid if valve is
detected and status is good.
GAS VALVE 2 - This green LED will light up when Gas Valve 2 is
modulating or commanded to modulate. LED will stay solid if valve is
detected and status is good.
No. of
Blinks
1 Valve 1 Not Detected
2 Valve 2 Not Detected
3 Valve 1 Proof of Flame Failure
4 Valve 2 Proof of Flame Failure
5 SAT Not Detected (Stand-Alone
Mode)
6 SAT Cutoff
7 Communication Failure
ALARM LED
(Blinks every 10 seconds)
Table 4: ALARM LED Blink Codes
20
MODGAS-XWR Technical Guide
NOT USED
HEAT ENABLE
LED
STATUS LED
ALARM LED
COMM LED
POWER LED
ALARM LED
MADE IN USA
YS102530 REV 1
WATTMASTER
CONTROLS
STATUS
ALARM
COMM
POWER
ANODE
RESET IN
SAT
GND
AUX AIN
GND
TROUBLESHOOTING
MODGAS-XWR CONTROLLER
(OE377-26-00060)
ALARM
I2C
CONNECT
M
MENU
CONTACT RATING
IS 1 AMP MAX
@ 24 VAC
PROOF OF IGNITION 1
PROOF OF IGNITION 2
GAS VALVE
TERMINALS
CONNECT
AUX BIN
HEATEN
OPTIONS
www.aaon.com
OE377-26-00060
MODGAS-XWR
INPUT TERMINALS (TYPE)
GND
AUX. (BI)
HEAT ENABLE (BI)
RESET INPUT (AI)
SAT INPUT (AI)
GND(AI)
AUX. (AI)
GND
WattMaster No:
#SW000055
GND
Rev.: 1A
+24 VAC
UP
DOWN
AAON No.: V20780
RELAY OUTPUT
TERMINALS
FAN
LOW SPEED
HEAT 1
HEAT 2
COMMON
GAS VALVE 1
GAS VALVE 2
E-BUS
ENTER
COMMON
PO-IGN1
ANODE
PO-IGN2
ANODE
Troubleshooting
RLY1
RLY2
RLY3
RLY4
GAS VALVE 1
GAS VALVE 2
FAN LED
LOW SPEED FAN LED
HEAT ENABLE 1 LED
HEAT ENABLE 2 LED
PROOF OF IGNITION 1 LED
GAS VALVE 1 LED
PROOF OF IGNITION 2 LED
GAS VALVE 2 LED
Figure 10: MODGAS-XWR Controller LED Locations and Descriptions
MODGAS-XWR Technical Guide
21
TROUBLESHOOTING
Troubleshooting Alarms
Troubleshooting Alarms
Mechanical Failure:
• Check relay outputs on the MODGAS-XWR for 24
VAC output.
• Verify the SAT OPTIONS jumper settings on the
MODGAS-XWR for Supply Air Temperature Sensor.
• Verify gas valve LED is solid. Try forcing valves (refer
to Force Screens in this guide).
• Verify that the Supply Air Temperature Sensor is
connected to SAT and GND on the MODGAS-XWR
(stand-alone mode) or to AI2 and GND on the Main
Controller (communicating mode).
• Verify Supply Air Temperature Sensor probe is
mounted correctly in supply duct.
• Remove SAT and GND wiring from the MODGAS XWR and ohm sensor out (this may indicate open or
failed wiring). Refer to chart in back of this guide for
readings.
Supply Air Temperature Failure:
• Verify that the Supply Air Temperature Sensor is
connected to the SAT and GND on the MODGAS XWR (stand-alone mode) or to AI2 and GND on the
Main Controller (communicating mode).
• Remove SAT and GND wiring from MODGAS-XWR
and ohm sensor out (this may indicate open or failed
wiring). Refer to chart in back of this guide for
readings.
• Verify the SAT OPTIONS jumper settings on the
MODGAS-XWR for the Supply Air Temperature
Sensor.
SAT Cutoff Mode:
• Remove SAT and GND wiring from the MODGAS XWR and ohm sensor out (this may indicate open or
failed wiring). Refer to chart in back of guide for
readings.
• With Supply Air Sensor disconnected from the
MODGAS-XWR, set volt meter to DC volts and
measure voltage between SAT and GND on board.
Refer to chart in back of this guide for readings.
• Verify Supply Air Temperature Sensor reading in duct
with 3rd party temperature testing device.
Communications Loss:
• Check COMM LED on MODGAS-XWR.
• Verify 24 VAC power to all interconnected WattMaster
controllers.
• Verify E-BUS connection between the MODGAS XWR and associated WattMaster controllers.
• In communication mode (connected to an AAON unit
Controller with modular cable), confi rm that Main
MODGAS screens shows COMM MODE that Main
Controller’s MODGAS status screen displays
MODGAS-XWR’s Position %.
22
MODGAS-XWR Technical Guide
TROUBLESHOOTING
Troubleshooting
Other Checks
0-3.3V (SAT OPTIONS Jumper Setting 1) &
0-5V (SAT OPTIONS Jumper Setting 2) Supply
Air Temperature Sensor
If you suspect the Supply Air Temperature Sensor is not reading correctly, make sure the wiring terminal connections are tight and that any
wiring splices are properly connected. Y ou can check the operation of the
Supply Air Temperature Sensor by measuring the resistance or voltage
using a digital multimeter. Set the meter to DC Volts. Place the positive
probe on the AIN terminal and the negative probe on the GND terminal.
Read the DC Volts and fi nd that voltage in Tables 5 & 6.
Read the temperature corresponding with that voltage and determine
if this is close to the actual temperature the sensor is exposed to. If the
temperature from the chart is different by more than a few degrees, you
probably have a defective or damaged sensor. You can also check the
sensor resistance to determine correct operation. T o read the resistance,
set the meter to Ohms. Unplug the sensor connector from the board and
measure the resistance across the disconnected wires. This resistance
should match the corresponding temperature from Tables 5 & 6.
Temperature to Resistance/Voltage Chart
Temp
(°F)
-10 -23.3 93333 2.98
-5 -20.6 80531 2.94
0 -17.8 69822 2.89
5 -15.0 60552 2.83
10 -12.2 52500 2.77
15 -9.4 45902 2.71
20 -6.7 40147 2.64
25 -3.9 35165 2.57
30 -1.1 30805 2.49
35 1.6 27140 2.41
40 4.4 23874 2.33
45 7.2 21094 2.24
50 10.0 18655 2.15
52 11.1 17799 2.11
54 12.2 16956 2.08
56 13.3 16164 2.04
58 14.4 15385 2.00
60 15.6 14681 1.96
62 16.7 14014 1.93
64 17.8 13382 1.89
66 18.9 12758 1.85
Table 5: 0-3.3 V Temperature Sensor - Voltage &
Resistance for Type III Sensors
Temp
(°C)
Resistance
(Ohms)
Voltage @
Input (VDC)
Temperature to Resistance/Voltage Chart
Temp
(°F)
68 20.0 12191 1.81
69 20.6 11906 1.79
70 21.1 11652 1.78
71 21.7 11379 1.76
72 22.2 11136 1.74
73 22.7 10878 1.72
74 23.3 10625 1.70
75 23.9 10398 1.68
76 24.4 10158 1.66
78 25.6 9711 1.63
80 27.8 9302 1.59
82 27.8 8893 1.55
84 28.9 8514 1.52
86 30.0 8153 1.48
88 31.1 7805 1.45
90 32.2 7472 1.41
95 35.0 6716 1.33
100 37.8 6047 1.24
105 40.6 5453 1.16
110 43.3 4923 1.09
115 46.1 4449 1.02
120 48.9 4030 .95
125 51.7 3656 .88
130 54.4 3317 .82
135 57.2 3015 .76
140 60.0 2743 .71
145 62.8 2502 .66
Temp
(°C)
Resistance
(Ohms)
Voltage @
Input (VDC)
Table 5, continued: 0-3.3 V Temperature Sensor Voltage & Resistance for Type III Sensors
Thermistor Sensor Testing Instructions
1.) Use the resistance column to check the thermistor sensor while disconnected from the controllers (not powered).
2.) Use the voltage column to check sensors while connected to powered
controllers. Read voltage with meter set on DC volts. Place the “-” (minus) lead on GND terminal and the “+” (plus) lead on the sensor input
terminal being investigated.
If the voltage is above 3.3 VDC, the sensor or wiring is “open.” If the
voltage is less than 0.05 VDC, the sensor or wiring is shorted.
MODGAS-XWR Technical Guide
23
TROUBLESHOOTING
Troubleshooting
Temperature to Resistance/Voltage Chart
Temp
(°F)
-10 -23.3 93333 4.620
-5 -20.6 80531 4.550
0 -17.8 69822 4.474
5 -15.0 60552 4.390
10 -12.2 52500 4.297
15 -9.4 45902 4.200
20 -6.7 40147 4.095
25 -3.9 35165 3.982
30 -1.1 30805 3.862
35 1.6 27140 3.737
40 4.4 23874 3.605
45 7.2 21094 3.470
50 10.0 18655 3.330
52 11.1 17799 3.275
54 12.2 16956 3.217
56 13.3 16164 3.160
58 14.4 15385 3.100
60 15.6 14681 3.042
62 16.7 14014 2.985
64 17.8 13382 2.927
66 18.9 12758 2.867
68 20.0 12191 2.810
69 20.6 11906 2.780
70 21.1 11652 2.752
71 21.7 11379 2.722
72 22.2 11136 2.695
73 22.7 10878 2.665
74 23.3 10625 2.635
75 23.9 10398 2.607
76 24.4 10158 2.577
78 25.6 9711 2.520
80 27.8 9302 2.465
82 27.8 8893 2.407
84 28.9 8514 2.352
86 30.0 8153 2.297
88 31.1 7805 2.242
90 32.2 7472 2.187
95 35.0 6716 2.055
Temp
(°C)
Resistance (Ohms) Voltage @
Input (VDC)
Temperature to Resistance/Voltage Chart
Temp
(°F)
100 37.8 6047 1.927
105 40.6 5453 1.805
110 43.3 4923 1.687
115 46.1 4449 1.575
120 48.9 4030 1.469
125 51.7 3656 1.369
130 54.4 3317 1.274
135 57.2 3015 1.185
140 60.0 2743 1.101
145 62.8 2502 1.024
150 65.6 2288 0.952
Temp
(°C)
Resistance (Ohms) Voltage @
Input (VDC)
Table 6, cont.: 0-5V Temperature Sensor - Voltage
& Resistance for Type III Sensors
Thermistor Sensor Testing Instructions
1.) Use the resistance column to check the thermistor sensor while
disconnected from the controllers (not powered).
2.) Use the voltage column to check sensors while connected to powered controllers. Read voltage with meter set on DC volts. Place the “-”
(minus) lead on GND terminal and the “+” (plus) lead on the sensor
input terminal being investigated.
If the voltage is above 5.08 VDC, the sensor or wiring is “open.” If the
voltage is less than 0.05 VDC, the sensor or wiring is shorted.
Table 6: 0-5V Temperature Sensor - Voltage &
Resistance for Type III Sensors
24
MODGAS-XWR Technical Guide
APPENDIX A
Supply Air Temperature Sensor Installation
Mounting the Supply Air Temperature
Sensor
• The Supply Air Temperature (SAT) Sensor should be
located in the duct-work downstream of the unit supply
air connection.
• Locate the sensor in the center of the widest part of the
duct. Use the supplied template and a 5/16” drill to make
a hole for the sensor.
• Install the gasket over the probe and mount securely to
the duct using the supplied sheet metal screws. Be sure
the gasket is compressed to provide an air tight seal.
• For best accuracy, apply insulation on the outside of the
duct, over the sensor. This will help prevent thermal
gradients from affecting the sensor.
WARNING: Make sure your Supply Air Temperature
Sensor is mounted and wired according to
these instructions prior to testing the unit or
else the modulating valve will not control
properly and may damage your equipment.
Stand-Alone Mode
In Stand-Alone Mode, the SAT Sensor is connected to the MODGASX Controller. If, in Stand-Alone Mode, the MODGAS-X Controller is
used in conjunction with a Stand-Alone MHGRV Controller, the SAT
sensor is shared between the two controllers and always attaches to the
MODGAS-X Controller.
See Table 8, page 26 for SAT Options Jumper Settings and see Figures
2, 4, 5 & 6 for wiring. See Table 7, page 26 for details about retrofi t
applications.
Communication Mode
When communicating with AAON Unit Controllers, the SAT Sensor
will be connected to the Main Controller. The exception would be in
retrofi t applications with older controllers. See T able 9, page 26 for SA T
Options Jumper Settings and see Figures 3 & 7 for wiring. See Table
7, page 26 for details about retrofi t applications.
Leads Are Non-Polarized. Butt Splice Leads
To 24 Gauge Wire Minimum.
In Stand Alone Applications And In Retrofit
Applications, Connect Leads to “SAT” And “GND” On
MODGAS-XWR Controller. See .
If Using A VCM-X Or VCB-X Controller, Connect Leads
To “AI2” And “GND” On Main Controller.
Table 7, Page 26
Figure 11: Supply Air Temperature Sensor Installation
MODGAS-XWR Technical Guide
25
APPENDIX A
SAT Sensor Wiring Guide & Jumper Settings
SAT Wiring Conditions
MODGAS-XWR ONLY MHGRV-X ONLY MODGAS-XWR & MHGRV-X
STAND-
ALONE
VCB-X,
VCC-X
VCM-X,
SA, RNE
VCM,
VAV/CAV,
MUA,
MUA II,
MUA IID
Install Supply Air
Sensor in MODGASXWR.
Install Supply Air Sensor
in VCB-X or VCC-X.
Connect to VCB-X or
VCC-X using E-BUS
cable.
Install Supply Air Sensor
in Main Controller.
Connect to Main
Controller using I
cable.
Install Supply Air Sensor
in MODGAS-XWR.
Connect to Main
Controller using I
cable.
2
C
2
C
Install Supply Air
Sensor in MHGRV-X.
Set “SAT Options”
Jumpers to “Normal”.
Install Supply Air
Sensor in VCB-X or
VCC-X. Connect to VCB-X
or VCC-X using E-BUS
cable.
Install Supply Air
Sensor in Main Controller.
Connect to Main
Controller using I2C cable.
Install Supply Air
Sensor in MHGRV-X.
Connect to Main
Controller using I2C cable.
Table 7: SAT Wiring Conditions
SAT Options Jumper Settings
Refer to Tables 8 & 9 to determine the settings. See Figure 2, page 5
for jumper locations.
STAND-ALONE MODE
SAT OPTIONS JUMPER SETTINGS*
CONDITION SETTING
MODGAS-XWR Only 1
MODGAS-XWR with
MHGRV-X** 1
MODGAS-XWR with
MHGRV II*** 2
MODGAS-XWR with
MHGRV III 2
* For SAT Sensor testing, use Table 5, page 23 for
jumper setting 1 and Table 6, page 24 for jumper
setting 2.
** In this situation, also set MHGRV-X SAT Option
to MODGAS-X. See the MHGRV-X Technical
Guide for more information.
*** The MHGRV II must have PU resistor installed.
Install Sensor in MODGAS-XWR and daisy-chain
it to the MHGRV-X. Set “SAT Options” Jumpers to
“MODGAS X”. If connected to a MODGAS II
Retrofi t, Set “SAT Options” Jumpers to “MODGAS”.
Install Supply Air Sensor in VCB-X or VCC-X.
Connect to VCB-X or VCC-X using E-BUS cable.
Install Supply Air Sensor in Main Controller.
Connect to Main Controller using I2C cable.
Install Supply Air Sensor in MODGAS-XWR.
Connect to Main Controller using I2C cable.
COMMUNICATIONS MODE
SAT OPTIONS JUMPER SETTINGS*
CONDITION SETTING
VCM-X / RNE / SA* 1
VCM, MUA, MUA II,
MUA IID VAV/CAV** 1
VCB-X / VCC-X* 1
* For SAT Sensor testing, use Table 5, page 23 for
jumper setting 1. SAT should be connected to the
Main Controller.
** For SAT Sensor testing, use Table 5, page 23
for jumper setting 1. SAT should be connected to
the MODGAS-X Controller.
Table 9: Communications Mode SAT OPTIONS
Jumper Settings
Table 8: Stand-Alone Mode SAT OPTIONS Jumper
Settings
26
MODGAS-XWR Technical Guide
APPENDIX B
MODGAS-XWR Replacement of MODGAS II
Replacing the MODGAS II with the
MODGAS-XWR
The retrofi t replacement involves a few easy steps. Refer to Figure
12, below.
STAND-ALONE MODE OPERATION
Step 1: Disconnect power from the MODGAS II Controller.
Step 2: Disconnect the Supply Air Temperature Sensor from the
MODGAS II and wire it to the MODGAS-XWR. If the Supply
Air Temperature Sensor is being shared with a Stand Alone MHGRV-X Controller, maintain the same wiring
with the MHGRV-X Controller.
Step 3:
Wire all other inputs and outputs per Figure 2, page 5.
Step 4: Set the SAT Options Jumper per Table 8, page 26.
Step 5: Connect power to the MODGAS-XWR Controller.
COMMUNICATIONS MODE OPERATION
Step 1: Disconnect power from the MODGAS-XWR Controller.
Step 2: The Supply Air Temperature Sensor needs to remain
installed on whatever controller it is currently on. If it
is currently installed on the MODGAS II Controller, then
reinstall it on the MODGAS-XWR Controller.
Step 3:
Set the SAT Options Jumper per Table 9, page 26.
Step 4: Connect power to the MODGAS-XWR Controller.
MODGAS-XWR CONTROLLER
(OE377-26-00060)
See Tables 8 & 9, Page 26
For
SAT OPTIONS
Settings.
Jumper
Only One Supply Air
Temperature Sensor
Can Be Used Per Application.
See Table 7, Page 26
For Connection Settings.
MADE IN USA
YS102530 REV 1
WATTMASTER
CONTROLS
RESET IN
SAT
GND
AUX AIN
GND
STATUS
ALARM
COMM
POWER
ANODE
AUX BIN
HEATEN
OPTIONS
ALARM
www.aaon.com
OE377-26-00060
MODGAS-XWR
INPUT TERMINALS (TYPE)
GND
AUX. (BI)
HEAT ENABLE (BI)
RESET INPUT (AI)
SAT INPUT (AI)
GND(AI)
AUX. (AI)
GND
WattMaster No:
#SW000055
GND
Rev.: 1A
+24 VAC
I2C
CONNECT
M
MENU
DOWN
AAON No.: V20780
CONTACT RATING
IS 1 AMP MAX
@ 24 VAC
LOW SPEED
COMMON
PROOF OF IGNITION 1
PROOF OF IGNITION 2
GAS VALVE
TERMINALS
E-BUS
CONNECT
UP
ENTER
RELAY OUTPUT
TERMINALS
FAN
HEAT 1
HEAT 2
GAS VALVE 1
GAS VALVE 2
2
I C Cable
Connects To
Main Controller’s
Expansion
Port
COMMON
PO-IGN1
ANODE
PO-IGN2
ANODE
RLY1
RLY2
RLY3
RLY4
GAS VALVE 1
GAS VALVE 2
Figure 12: MODGAS-XWR Controller
MODGAS-XWR Technical Guide
27
www.aaon.com
2425 So. Yukon Ave • Tulsa, OK 74107-2728
Ph: (918) 583-2266 • Fax: (918) 583-6094
AAON® Manual Part No. V22330
WattMaster Manual Form No: AA-MODGASXWR-TGD-01B
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