Edge [ii] Controller Operation Manual
SECTION 6
– ADVANCED SETUP
OMM-139_E
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of
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2. In
Select Output
, choose either:
•
Cascade Valve
:
For use with AERCO supplied valves.
•
Aout 2
: For controlling non-AERCO supplied valves.
3. The following parameters appear for both values of
Select Output
:
•
Output Signal Type
: Select the output signal type of the selected output:
Current
or
Voltage
.
•
Control Mode
: Choose one:
On/Off
,
Linear Modulation
or
Delta T Modulation
.
•
Valve Feedback
: Choose
Enabled
or
Disabled
. If Enabled, the following additional
parameters appear:
o
Valve Feedback Status
: A read-only display of the current valve status.
o
Valve Feedback Timer
: The time to detect the
Valve Feedback Status
(Range: 30 to 240 sec.)
•
Valve Balancing
: If you wish to implement the Valve Balancing feature on the
cascade, set this parameter to
Enabled
, then go to
and complete the instructions there.
•
Min # Valves Open
: This parameter appears only if
Unit Mode
=
BST Manager
). Specify the minimum number of isolation
valves that must stay open at all times, including during plant standby conditions. The
number specified appears on the Isolation Valve Status screen (see
This ensures the boiler’s maximum flow is not exceeded at low
loads and helps reduce the flow rate during plant standby. To determine the value for
Min # Valves Open, use the following formula, rounding up the result to the higher
number:
Min # Valves Open
= (Pump’s minimum flow rate / Boiler maximum flow rate
).
4. The following parameters appear only if
Select Output
=
Aout 2
:
A.
Open Vlv Control Signal
: Select the signal that
will “fully open” the valve:
0 mA
,
4 mA
or
20 mA
.
B.
Close Vlv Control Signal
: Select the signal that
will “fully close” the valve:
0 mA
,
4 mA
or
20 mA
.
Reserve Unit Control
The
Reserve Unit Control
screen allows you to enable the Reserve Unit Control feature, which
will
activate a “Reserve Unit” in the event the plant cannot keep up with the system load.
NOTE
:
This screen is available only after BST Cascade functionality has been enabled (see the
Unit Mode
parameter in
). If the unit is configured as
a
BST Manager
, its parameters apply to this unit and all
BST Client
units. If the unit is
configured as a
BST Client
, the parameters configured on the
BST Manager
will take
precedence.
1. Go to:
Main Menu
→
Advanced Setup
→
BST Cascade
→
Operating Controls
→
Reserve Unit Control
.