Honeywell BCU 460 User Manual

BCU 460, BCU 465 · Edition 11.19 11
Application
1.1.4 Modulating control with defined ignition
position
VAS VAG
V1 V2
V3
UVS
VAS 1
BCU 460..F1
60 61 62 65 66
22
3 6
µC
81
82
95
96
35
2
Process control (PCC)
P
4
A
1
Start 1
HT
40 41
BVA
IC 40
4
12
16
DI 1
7
DI 2
M
µC
18
IN
mA
FCU 500 PLC
The central control system starts the pre-purge. Input
DI2 is activated via the air valve output of the BCU and
the butterfly valve BVA is set to the pre-purge position.
In the event of a temperature demand, the burner con-
trol unit BCU activates input DI1 via the output at ter-
minal 65 and moves the butterfly valve to the ignition
position (condition: the IC40 must have reached the
ignition position on the instant of ignition). The burner
starts.
The burner application “Burner 1 with pilot gas” (pa-
rameter A078=1) is selected so that the burner can be
started with a limited start fuel flow rate.
During operation, the BCU activates DI1 and DI2 using
outputs 65 and66. This enables the analogue input IN
on the actuator IC40. Depending on the capacity de-
mand of the temperature controller, the butterfly valve
BVA moves steplessly between the low-fire rate and the
high-fire rate to the position specified by the analogue
input IN, see page110 (Operating mode 27).
DI 1/V1 DI 2/Air valve IC 40 position Valve position
Off Off closed Closed
On Off low
Ignition position/Low-
fire rate
On On analogue chart 1 In acc. with chart 1
Off On high Pre-purge/High-fire rate

Honeywell BCU 460 Specifications

General

Brand	Honeywell
Model	BCU 460
Category	Control Unit
Language	English