Bryan Boilers 250 Boiler User Manual


 
Date: 8-4-2010
Revision: 0
Form: 2396
Baseload common (i) “BL” for baseload (ii)User
selection 0 – 100 % (d)Use existing timeout,
Done button, and Next button functionality to
enter these parameters. (e)User selections will
be selected by MMI. (i) The local display does
not adhere to the PCB (OEM parameter
selections used by S7999). (5) In normal display
operation the display allows a user to scroll
through a list of temperatures with associated
icons (CH, Inlet, Delta, DHW, Stack, Outdoor)
using the Next button. With LL active the display
will show the header temperature at the end of
the list of temperatures as follows: (a)The
characters “LL” are displayed in the number field
(b)When the next button is pressed again the
temperature is displayed. (c) If the Up or Down
buttons are pressed then the LL set-point is
changed. 5. System Display Configuration – The
following parameters are available for OEM
configuration and may be adjusted through a
System Display or programmed at the OEM
production facility. Master Sola Slave Sola LL
frost protection enable Slave mode LL frost
protection rate Base load rate Base load rate
Slave sequence order LL CH demand switch LL
Demand to firing delay LL CH set point source
LL Modulation sensor LL Base load common LL
Modulation backup sensor LL CH 4mA water
temperature LL Lead selection method LL CH
20mA water temperature LL Lag selection
method LL Add stage method 1 LL Add stage
detection time 1 LL Add stage error threshold LL
Add stage rate offset LL Add stage inter-stage
delay LL Drop stage method 1 LL Drop stage
detection time 1 LL Drop stage error threshold
LL Drop stage rate offset LL Lead rotation time
LL Force lead rotation time LL Drop stage inter-
stage delay
4.5 SLAVE OPERATION AND SETUP
Slave Data Supporting Lead Lag
This data is provided by each slave Sola control
to support operation when a LL master exists.
The illustration below summarizes the slave's
registers and data:
LL Slave
Some slave changes relate to pump control,
frost protection, and also are available to 3
rd
party (non Sola) LL master devices. The generic
LL slave is updated to operate as shown by the
diagram below:
Frost protection requests
The frost protection in this status register will be
set or cleared to match the status generated by
the frost protection detection functions.
Firing for local frost protection This
provides indication to the LL master that
although the burner is firing independently, it is
doing so for frost protection and thus is still
available as a lead/lag slave. This is set when 1)
frost protection is controlling the Sola per the
priority scheme (which occurs only if frost
protection is enabled), and 2) burner demand is
true and the burner is currently firing or
preparing to fire to serve that demand.
Otherwise it will be clear.
Aux Pump X, Y, and Z The pump control in
the Slave can be used by previously existing
command devices to create the same behavior.
However before these bits controlled actions is
specific pump blocks, they are now more
general. The pump X, Y, and Z bits control
actions in any pump block defined to handle
them (see the pump control block definition).
4.6 SLAVE PARAMETERS
SLAVE ENABLE: DISABLE, ENABLE VIA
MODBUS, ENABLE FOR SOLA MASTER
It enables or disables the "LL Slave" Demand
and Rate module. If the slave mode is set to
Disable then: none of the slave functions are
active, Slave Status register is zero, the LL –
Master Service Status register is not writable
and is held at zero (this is important for pump
control which might otherwise use values in this
location). The Slave Command register is
writable but it is mostly ignored, however the
Aux pump X, Y, and Z are effective for any
setting of the Slave enable parameter. The
Enable for Sola Master option Slave write and
Slave read parameters; if "Enable for Sola
Master" is not selected, then these parameters
are disabled.
SLAVE MODE: USE FIRST, EQUALIZE
RUNTIME, USE LAST
If set to Use First, then this Sola will be used
prior to using other Solas with other values. If
set to Equalize Runtime, then this Sola will be
staged according to a run time equalization
60