76
Wiring the Outdoor Sensor
There is no connection required if an outdoor sensor is not used in this installation.
Connect the Outdoor Sensor wires to the terminals
8 and 9
marked
‘Outdoor Sensor’
shown in
on page 66. Caution should be used to ensure neither of these terminals becomes connected to
earth.
Use a minimum 1mm wire for runs of up to 45m.
Mount the outdoor sensor on an exterior surface of the building, preferably on the north side in an area
that will not be affected by direct sunlight and that will be exposed to varying weather conditions, shown
as S4 in the diagrams,
on page 69.
CAUTION:
Sensor and control wiring must
NOT
be run in conduit or chases with line voltage.
0-10 Volt Energy Management System (EMS)
A signal from an energy management system may be connected to the MVB water heater. This signal
should be a 0-10 Volt positive DC signal, and an energy management system can be used to control
either the set point temperature of a single MVB or a cascade of up to 4 water heaters, or the firing rate
of a single MVB water heater.
To enable this remote control function, set
dip switch 5
to the UP position on the PIM™ (refer to
on page 71).
Dip switch 5 Toggles between a signal from the EMS (UP) or a demand signal from the VERSA
(DOWN).
Dip switch 2 on the PIM™ toggles between a Direct Drive input of the modulation rate (UP) and a Target
Temperature set point (DOWN).
With Dip switch 5 in the UP position and when:
•
Dip switch 2 is UP, the 0-10V will control the modulation rate and the programmed temperature will
be the target.
•
Dip switch 2 is DOWN, the 0-10V will change the target temperature and the modulation rate will
be the result of the difference between the set point and measured temperature.
Connect an Energy Management System or other auxiliary control signal to the terminals
13 and 14
marked
‘
0-10V EMS INPUT
’
on field wiring terminal strip, refer to
on page 76. Caution should
be used to ensure that the 0-10V connection does not create a short to earth.
For a 4-20mA application, Dip switch 6 must be in the ON (UP) position and a 500 Ohm ½ Watt resistor
is wired in parallel across the +/- terminals.
Fig 43: PIM connections and DIP Switch Location
DIP Switches
TO TERMINALS 13/14
