1. Voyager II and III – Energy Recovery Modules
Operation and Control
Ph.TISSERAND
October 2010

2. Energy Recovery Module installation
Easy installation of the two sub-assemblies
Rooftop unit is designed to receive Energy Recovery Module (ERM).
Rooftop will contain all control equipment : TR1-2800®, Economizer Module (ECA), Connection Terminal, Temperature sensors, defrost pressure switch/timer relay.
Rooftop
ERM

3. Energy Recovery Module installation
Easy electrical connection into the rooftop
Exhaust fan power cables and actuator motor cables prepared
ERM
Cables connected to terminal block inside the rooftop
Installation and startup procedure described in document RT-SVX42A

4. Voyager II / Voyager III concept
Mixing between return and fresh air is not managed in the rooftop but in the ERM
Return air duct is connected to ERM
Voyager III
In PHE version, the mixing between return and fresh air is done inside the rooftop.
Return air duct is located as the same place as standard rooftop unit.
In ERW version, mixing between return air and fresh air is done inside the ERM
PHE
Exhaust fan treat only exhaust air flow.
Exhaust fan is variable speed according to fresh air %
Standard : a defrost pressure switch that initiate defrost cycle (bypass of PHE) during a pre-set timer sequence
Condensation evacuate via drain pipe.
ERW
Exhaust fan treat 100% of the air flow (Return fan).
Exhaust fan airflow as to be set at commissioning, but remains fixed speed during operation.
No condensate to evacuate, moisture transferred between the 2 airflow.

5. Voyager II
PHE
GDR
FRD
HTX
BPD
EXF
ROOFTOP
MXD
FLT
ERW
LVR
Voyager II
Mixing between return and fresh air is not managed in the rooftop but in the ERM
Return air duct is connected to ERM
PHE
Exhaust fan treat only exhaust air flow.
Exhaust fan is variable speed according to fresh air %
Standard : a defrost pressure switch that initiate defrost cycle (bypass of PHE) during a pre-set timer sequence
Condensation evacuate via drain pipe.
ERW
Exhaust fan treat 100% of the air flow (Return fan).
Exhaust fan airflow as to be set at commissioning, but remains fixed speed during operation.
No condensate to evacuate, moisture transferred between the 2 airflow.
HTX
FLT
ROOFTOP
MXD
EXF
GDR

6. Voyager III PHE 275-300-350-400-500-600 ERW 275-300-350-400-500-600
GDR
ROOFTOP
HTX
BPD
EXF
FLT
ERW
LVR
ROOFTOP
Voyager III
In PHE version, the mixing between return and fresh air is done inside the rooftop.
Return air duct is located as the same place as standard rooftop unit.
In ERW version, mixing between return air and fresh air is done inside the ERM
PHE
Exhaust fan treat only exhaust air flow.
Exhaust fan is variable speed according to fresh air %
Standard : a defrost pressure switch that initiate defrost cycle (bypass of PHE) during a pre-set timer sequence
Condensation evacuate via drain pipe.
ERW
Exhaust fan treat 100% of the air flow (Return fan).
Exhaust fan airflow as to be set at commissioning, but remains fixed speed during operation.
No condensate to evacuate, moisture transferred between the 2 airflow.
HTX
FLT
MXD
EXF
GDR

7. Legend Modulating Fresh air damper Modulating Mixed air damper
FRD
MXD
GDR
Modulating Fresh air damper
Modulating Mixed air damper
With 0-10VDC / 24VAC actuator
Gravity exhaust damper
HTX
Heat recovery exchanger
EXF
Exhaust fan
BPD
By-pass damper
With 24VAC ON/OFF actuator
Mixed air flow
FLT
Fresh air flow
EU3 Air filter
LVR
Return air flow
Fresh air weather louver

8. Key control components - PHE version
Rooftop
Supply fan
Indoor rooftop supply fan (ON-OFF)
VarioTrane TR1-2800
(Speed inverter)
Power OUT
Exhaust fan
Power IN
Reliatel controller
(RTRM-RTOM)
Outdoor air T°
2-10 VDC
input
Mixing/Fresh air damper actuator
(Voyager II only)
Return air T°
Mixed air T°
ECA module
(Economizer Control Actuator)
ON-OFF input
By-pass damper actuator
(ON in free-cooling mode)
Defrost pressure
switch / timer relay

9. Key control components - ERW version
Rooftop
Supply fan
Indoor rooftop supply fan (ON-OFF)
VarioTrane TR1-2800
(Speed inverter)
Return fan
Power IN
Power OUT
Fixed Reference
Reliatel controller
(RTRM-RTOM)
Outdoor air T°
Return air T°
Mixed air T°
ECA module
(Economizer Control Actuator)
2-10 VDC
input
Mixing damper actuator
Heat wheel motor
(OFF in free-cooling mode)
ON-OFF input

10. Energy Recovery Module operation
ERM operation is following the rooftop fan and economizer operation
ERM
Exhaust fan
Rooftop
Supply fan
Economizer
Fresh air damper
Unit status
Unit
Fan
THP 03
Fan AUTO Without
cooling / heating demand
OFF 0%
Unit OFF
Ventilation mode
Cooling mode
Heating mode ON
Min %
Min % (PHE)
100% (ERW)
Unit ON
Unit in free cooling ON
100%
Free cooling

11. Ventilation mode
Fresh air setting
The minimum fresh air opening is setup through the ECA minimum opening onboard potentiometer (0 to 50%).
Minimum opening setting could also be given by Tracker / BCU or LON BMS.
CO2 sensor option has to be used to adjust fresh air % according to occupancy.
On PHE version, exhaust fan motor minimum frequency has to be adjusted through TR1-2800® parameter
Mechanical Cooling - Heating
Unit controls cooling and heating stages with the same logic as a unit without Energy recovery option.
Defrost pressure switch / timer relay
INACTIVE
ECA
VarioTrane
Example for 20% fresh air setting on PHE – Voyager III version
3.6VDC
20%
By-pass damper OFF
ROOFTOP
100 20 20 20 20 80 20 20
100
100

12. Free cooling mode Example of 100% free cooling
Free cooling initiation
If the zone is calling from cooling, if Outdoor air temperature is lower than return air temperature, the free cooling will be enabled.
In free cooling operation, the ECA will drive fresh air damper modulating from minimum opening to 100% depending of zone cooling need and mixed air temperature.
Energy Recovery control
The plate heat exchanger by-pass damper is controlled in open/close position depending of fresh air damper position. In free cooling mode, the by-pass damper will open, causing fresh air to flow beside the plate heat exchanger. So, Fresh air temperature will not modified by the heat exchanger.
On PHE version, as fresh air introduction increased, the exhaust fan speed increased up to 100% in order to avoid building pressurization.
Defrost pressure switch / timer relay
INACTIVE
ECA
VarioTrane
Example of 100% free cooling
on PHE – Voyager III version
10VDC
100%
By-pass damper ON
100
ROOFTOP
100
100
100
100
100
100
100
100

13. Defrost mode (PHE versions only)
During cold period of winter, entering fresh air is at negative temperature. Condensate water on the exhaust side of the PHE could freeze causing pressure drop to increase.
A differential pressure switch will sense the pressure drop on the exhaust air side of the PHE. When threshold set point is reached (Frozen PHE), the pressure switch initiate a 5 minutes timer relay that activates the by-pass damper actuator.
In absence of heat exchange, exhaust air flow will melt the ice on the heat exchanger.
During defrost cycle , the fresh air flow remains at minimum setting in order to be mixed with return air . Tempered air is introduced in the zone.
Defrost pressure switch / timer relay
ACTIVE
ECA
VarioTrane
Example of defrost cycle
on PHE – Voyager III version
3.6VDC
20%
By-pass damper ON
100 20
ROOFTOP 20 20 80 20 20 20
100
100
Water
evacuation

14. Thank you!