Lochinvar 5 사용자 설명서

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Installation & Operation Manual
7  
Field wiring   
System supply sensor
1.  By installing the system supply sensor into the supply 
of the primary loop, the temperature of the system 
supply can be controlled.  The SMART TOUCH control 
automatically detects the presence of this sensor, and 
controls the boiler firing rate to maintain the system 
supply temperature to the set point.  
2.  Connect these terminals to the system supply sensor 
 
 
 
 
 
(FIG. 7-3).
Boiler management system
1.  An external control may be connected to control either 
the firing rate or the set point of the boiler.  Connect the 
0 - 10 VDC terminals to the 0 - 10 VDC output of the 
external control.  The SMART TOUCH control can be 
enabled using the Enable output (see page 39) or using 
the voltage applied to the 0 - 10 VDC input.  Reference 
the SYNC Service Manual for more details.
2.  Make sure the ground terminal is connected to the 
ground output terminal of the external control, and the   
0 - 10 VDC terminal is connected to the 0 - 10 VDC 
terminal of the external control.
Runtime contacts
The SMART TOUCH control closes a set of dry contacts 
whenever the burner is running.  This is typically used by 
Building Management Systems to verify that the boiler is 
responding to a call for heat.
Alarm contacts
The SMART TOUCH control closes another set of contacts 
whenever the boiler is locked out or the power is turned off.  
This can be used to turn on an alarm, or signal a Building 
Management System that the boiler is down.  Note that these 
contacts will close momentarily at the end of each call for heat 
or at least every 24 hours.
Wiring of the cascade
When wiring the boilers for Cascade operation, select one boiler 
as the Leader boiler. The remaining boilers will be designated 
as Members.  See page 48 “Configuration of the Cascade” for a 
detailed explanation of this procedure.
Connect the system supply sensor and outdoor air sensor (if 
used) to the Leader boiler. For the Cascade system to work 
properly the system supply sensor must be installed. 
The location of the system supply sensor should be downstream 
of the boiler connections in the main system loop (FIG.’s 5-5 
and 5-6). The system supply sensor should be wired to the Low 
Voltage Connection Board at the terminals marked for the 
system supply sensor (see FIG. 7-3). The Leader control will use 
the water temperature at the system supply sensor to control the 
operation of the Cascade. 
If outdoor air reset is desired, the outdoor air sensor should be 
wired to the Low Voltage Connection Board at the terminals 
marked  for  the  outdoor  air  sensor  on  the  Leader  boiler           
(FIG. 7-3). If the outdoor air sensor is connected, the Leader 
control will calculate the water temperature set point based 
on the programmed reset curve parameters. If the outdoor air 
sensor is not connected, the Leader control will maintain the 
fixed water temperature set point that is programmed into the 
control. 
If a Thermostat or Zone Control enable output is available, it 
should be wired to the Low Voltage Connection Board on the 
Leader boiler at the terminals marked Enable (FIG. 7-3).  If  the 
boilers are to run continuously, connect a jumper wire between 
the R and W terminals at the Enable input. This will initiate a 
call for heat on the Cascade.  If the SMART TOUCH control 
is being controlled by a Boiler Management System (BMS), 
a  call  for  heat  may  be  initiated  by  the  voltage  applied  to  the                     
0 - 10 VDC input. 
Communication between the Leader boiler and the Member 
boilers is accomplished by using shielded, 2-wire twisted pair 
communication cable. Connect one of the twisted pair wires 
to terminal A on each of the Low Voltage Connection boards, 
and the other wire of the twisted pair to terminal B on each 
of the Low Voltage Connection Boards.  Connect the shield 
wires to one of the shield ground terminals on the Low Voltage 
Connection Boards (FIG. 7-3).  If more than two boilers are 
on the Cascade, daisy chain the wiring from the Sequencing 
terminals on the second boiler to the Sequencing terminals on 
the third boiler, then from the third to the forth, and so on. 
The connections between boilers can be made in any order, 
regardless of the addresses of the boilers.  Try to keep each cable 
as short as possible.
 NOTICE
A system supply sensor (factory supplied) 
MUST BE installed for proper boiler 
operation.
 NOTICE
A system supply sensor (factory supplied) 
MUST BE installed for proper boiler 
operation.
 NOTICE
DO NOT INSTALL THE SYSTEM 
SUPPLY SENSOR INTO THE SYSTEM 
RETURN.