Valve Balancing - Watts AERCO Edge [ii] Operation Manual

Edge [ii] Controller Operation Manual
SECTION 6 – ADVANCED SETUP

Valve Balancing

NOTE:
This screen is available only after BST Cascade functionality has been enabled (see the
Unit Mode parameter in
feature has been enabled in
a BST Manager, the 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.
The Valve Balancing screen is used to setup and configure the Balanced Flow Isolation
Valve feature. The goal of this feature is to raise or lower all unit's current T (water outlet
temp minus water inlet temp) to match the plant's target T, thereby balancing the load across
multiple boilers in a BST cascade.
Prior to balancing, in normal operation all isolation valves are either fully closed or fully open
(0% or 100% open). Valve balancing is accomplished by reducing the isolation valve's "fully
open" position, thereby restricting the flow from the unit's hot water outlet, as needed, until the
unit's T matches the plant's target T. This is repeated on the other units in the BST cascade
until each unit's T is approximately the same.
The isolation valve's "fully open" position is controlled by the number of volts sent to the valve;
before balancing 0.00V = "fully open". Adjusting the "fully open" position is accomplished by
raising the voltage to something above 0.00V. After balancing, the new voltage is used to open
the valve when the boiler is firing. The "fully closed" voltage does not change.
The procedure described above is performed from the unit designated as the BST Manager; at
completion the BST Manager transmits the new voltage to each unit in the cascade.
Once valve balancing has been completed, the final step is to physically go to each isolation
valve and manually configure it to send the "valve open" signal to the Controller when it gets to
the new "fully open" position. Once in operation, each time the isolation valve is activated, it will
go to the new open position and send a "valve open" signal to the Controller, allowing ignition to
proceed.
Before starting this procedure, determine the T the plant was designed for.
Main Menu → Advanced Setup → BST Cascade → Operating Controls → Valve
1. Go to:
Balancing. If this option is disabled, go to:
Cascade → Operating Controls → Valve Configuration
parameter to Enabled.
Figure 6.3.4.8-1: Operating Controls: Valve Balancing
•
OMM-139_E 8/25/2020
Section 6.3.1: Cascade
Section 6.3.4.4: Valve
Main Menu → Advanced Setup → BST
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Configuration) and the Valve Balancing
Configuration. If the unit is configured as
and set the Valve Balancing
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