FCU 500, FCU 505 · Edition 02.17 113
Parameters
12.6 Behaviour during start-up
12.6.1 Minimum pause time t
MP
Parameter 62
A minimum pause time t
MP
(0 to 3600 s) can be defined
to achieve stable operation of the heating equipment.
If the post-purge time t
PN
(parameter 37) has elapsed
and no signal (ϑ) is received at terminal 1 (furnace shut
down), a restart is prevented for the duration of the
minimum pause time t
MP
.
12.6.2 Switch-on delay time t
E
Parameter 63
Defines the time between applying the start-up signal
(start) and initiating the furnace start (0 to 25 s).
When several FCU 505 (zone FCUs) are activated si-
multaneously, setting different switch-on delay times t
E
prevents the fans from starting at the same time and
reduces the load on the power supply. The switch-on
delay also applies to the TC function.
12.6.3 Filling time before start-up
Parameter 65
The filling time for the pressure build-up in the gas line
before start-up is defined using this parameter. This
allows the tripping of the safety shut-off valve to be
prevented after the main gas valves have been released.
Bypass valves V3 and V4 are required for the slow pres-
sure build-up in test volume V
p2
.
p
u
/2
PZ
V
p1
V
p2
V1 V2
V3 V4
VAS
1557
(max. 0,5 A, cos ϕ = 1)
1314
The filling time can be set from 0 to 25 s.
The current supplied via terminal 57 to control valves V1
and V2 is max. 0.5 A. In the event that a higher output
current is required, the output current can be increased
by the additional connection of 2 contactors with
forced-guided contacts, see also page 127 (Safety in-
terlock output in the case of higher power requirement).
To Next Page
