Watts AERCO KC Series, Руководство пользователя

Страница: 32 / 82

MODE OF OPERATION
27
from an external source, the following functions
must be correctly set.
MENU FUNCTION SETTING
Secondary Lore re
Secondary FUNC Cont
Primary Auto OFF
5.5.1 BOILER MANAGEMENT SYSTEM
EXTERNAL FIELD WIRING
Wiring for this system is from the BMS panel to
terminals 2 and 3 in the unit’s external field
wiring box. Wire the units using a twisted pair of
22 gauge minimum wire. No shield is necessary.
When wiring multiple units, each unit’s wiring
must conform to the above. For a complete BMS
wiring diagram, see wiring schematic #18973
located in Appendix H.
5.5.2 BOILER MANAGEMENT SYSTEM
SETUP AND STARTUP
This mode of operation is factory preset and the
firing rate is controlled by the AERCO BMS
Model 168. There are no setup instructions for
each individual unit. However the unit must be
taken out of remote mode, and set to local
mode, to manually run the unit. Once finished
with manual mode it is necessary to set the unit
back to remote mode for it to be controlled by
the BMS.
To set the unit in local mode do the following:
1. Access the temperature controller’s
secondary menu.
2. Scroll through the menu until "lore" is
displayed.
3. Use
the
ž
keys to set the temperature
controller to local. The yellow REM light, on
the temperature controller, should extinguish
4. Press ENTER to accept the change.
5. Follow the above directions to change back
to remote mode.
NOTE:
The unit automatically defaults to remote
mode upon AC power being applied. This is
due to the presence of the external interface
board .
5.6 COMBINATION CONTROL SYSTEM
(CCP)
A Combination Control System is when enough
units are installed to cover the space-heating
load on the design day. However one or more of
the units are used to heat domestic, water while
the remaining units take care of the heating
load. The units used for the domestic hot water
are designated as the combination units and are
referred to as the combo units. The combo units
heat water to a constant setpoint temperature
that is circulated through a heat exchanger in a
domestic hot water tank.
An AERCO BMS 168 panel, a Combination
Control Panel (CCP), and the units are
interfaced in this mode of operation. When the
space heating units are all at 100% firing rate,
the BMS asks the CCP to switch the Combo
boilers to space heating mode. If the domestic
load is satisfied, the aquastat on the domestic
tank is open, the combo units will switch over to
space heating. If the domestic load is not
satisfied, the combo units remain on the
domestic load. If the combo units switch over to
space heating but there is a call for domestic hot
water, the CCP switches the combo units back
to the domestic load.
When the combo units are satisfying the
domestic load, they are in constant setpoint
mode of operation. When the combo units
switch over to space heating, their mode of
operation becomes BMS mode. For more
information concerning the operation of the
Combination Control Panel, see the AERCO
CCP-1 literature.
In CCP mode, the external interface board is
utilized. The interface board, located in the field
wiring box, is factory configured, and converts
the pulse width modulation signal, sent from the
BMS, to an RS-485 signal. The RS-485 signal is
then sent to the temperature controller. For the
temperature controller to recognize a signal,
from an external source, the following functions
must be correctly set.
MENU FUNCTION SETTING
Secondary Lore re
Secondary FUNC Cont
Primary Auto ON