Forced Part Load Time (*) - REMEHA Gas 310 ECO Technical Information

13.2.3 Forced part load time (*)

Parameter Adjustable between 0 and 300 seconds.
The boiler always starts with a specified output for a
certain time. The boiler can then be sent to the minimum
position (20% of output) for a specific period, independ-
ent of the heat demand.
13.2.4 Cycling prevention delay time (()
Parameter *, Adjustable between 0 and 300 seconds.
This value sets a minimum off time following a control
stop / end of a heat demand to prevent cycling taking
place. When after this delay time flow temperature lies
less than 5° above return temperature (check on water
flow), the boiler will restart.
13.2.5 Required flow temperature at 0 - 10 volts (a
and B)
Start point (0 volts): parameter a, adjustable between
-50° and +50°.
This value sets the required flow temperature at 0-volt
signal input.
End point (10 volts): parameter B, adjustable between
+51° and +249°.
This value sets the required flow temperature at 10-volt
signal input (restricted by the maximum flow tempera-
ture setpoint and the maximum output).
These settings only apply if boiler control 41 has
been selected: 'external analog input 0-10V on the basis
of flow temperature'.
fig. 27 Temperature control via analog (0-10 Volt)
signal
pdf
62560.indd 40 62560.indd 40
Gas 310 ECO
13.2.6 Switch point high/low operation signal (C)
Parameter C, adjustable between 0 and 60 (x 100)
rpm. This parameter enables setting the switch point
between "low fire" and "high fire". A fan speed below
the set value will cause a "low fire" signal. A fan speed
above the set value will cause a "high fire" signal.
An "ON/OFF" signal can be obtained by setting param-
eter c to 6000 rpm.
13.2.7 Shunt pump post-circulation time (D)
Parameter D, setting 00 = 10 sec; 99 = continu-
ous and adjustable between 01 and 15 = number
of minutes.
Continuous water circulation is advisable if there is a
danger of the heating system freezing up.
13.2.8 dT from control stop point to start point (E)
Parameter E, adjustable from 5 to 20°.
This value sets the flow temperature at which the boiler
will cut back in after a control stop.
The boiler will always go to a control stop when the flow
temperature equals the flow setpoint temperature + 5°.
The dT defines when the burner is switched on again.
A value of 10° indicates that the temperature has to
drop 5° below the calculated flow temperature set point
before the boiler starts to run again.
Cut back in temperature = flow setpoint (80) + 5 -
parameter E (10), i.e. 80 + 5 - 10 = 75°.
13.2.9 Maximum flue gas temperature (F)
Parameter F, adjustable between 80 and 120°.
This value sets the maximum operating flue gas tem-
perature - for use with PVC flue systems.
13.2.10 High limit temperature setting (G)
Parameter G, adjustable between 90 and 110°.
This value sets the high limit temperature at which the
boiler will shutdown in a lockout condition requiring
manual intervention.
Important!!
g
If the factory setting is reduced, a
corresponding reduction in flow setpoint will be required
otherwise the min flow rate may be effected.
13.2.11 Modulation start point at dT (H)
Parameter H, adjustable between 10 and 30°.
This value sets the flow/ return dT point at which the
control modulation begins. The boiler starts to modu-
late at the setpoint and will be at minimum output if the
dT continues to rise to 40°. At 45° the boiler will shut
(shut-off code b #)). For installations with low flow
rates the starting point modulation can be brought for-
ward (i.e. 15°), closer matching boiler output to system
demand. In systems with small volume flows the modu-
lation start point can be brought forward. The boiler is
better equipped to anticipate low heat demand.
The factory setpoint should be correct for most instal-
lations. The start point should only be changed if abso-
lutely necessary.
40
Remeha
18-6-2009 13:15:00 18-6-2009 13:15:00