MPT
700
23
3.6 Mode of operation 6 - heating/cooling with fixed pulse width
and separate air and gas valve control
•
The pulse width is set to a fixed value for each channel. ( air- and gas valve )
The pulse widths for the air valves can be set in parameter 40,42,44,46 and for
the gas valves in parameter 41,43,45,47.
•
If the setting is changed, the pulse spacing is changed.
•
Max. pulse frequency = 1 / (pulse width + minimum off time)
•
Even before the unit changes from pulse operation to a continuous pulse, the
minimum off time never falls below the set parameter value.
•
Setting source: heating/cooling limit and heating/cooling dead zone adjustable
(see diagram in section 4.11)
•
Outputs 1-3-5-7 control the air valves.
•
Outputs 2-4-6-8 control the corresponding gas valves.
•
The ignition timing for outputs 1-3-5-7 must be set.
•
Outputs 2-4-6-8 are activated with the set delay following outputs 1-3-5-7.
•
Any ignition timing entered for outputs 2-4-6-8 is not effective.
•
In cooling operation, only outputs 1-3-5-7 (air valves) are active.
•
In 128 mode, the output heating/cooling 1 and heating/cooling 2 is also used for
heating/cooling.
⇒
output inactive:
cooling
output active: heating
delay
≤
pulse width for air valves (1-3-5-7) + min. off time
ZZP: ignition timing
Pulse diagram:
ZZP
Output 2-4-6-8 gas valves
Output 1-3-5-7 air valves
delay
delay + pulse width gas valve pulse width air valve
delay + pulse width gas valve pulse width air valve
