64
Low Voltage (24 VAC) Connections - see Figure 44.
3. The terminal block TB-2 in conjunction with
terminal screw identification label is attached to
the junction box front and located inside Sage2.1
Control compartment on the left side.
4. The connections are (listed identification label top to
bottom):
• 1 – “Heating Thermostat”
• 2 – “Heating Thermostat”
• 3 – “DHW Temperature Switch”
• 4 – “DHW Temperature Switch”
• 5 – “Outdoor Sensor”
• 6 – “Outdoor Sensor”
• 7 – “Header Sensor”
• 8 – “Header Sensor”
• 9 – “Remote Firing Rate -”
• 10 – “Remote Firing Rate +”
• 11 – “External Limit”
• 12 – “External Limit”
5. If the outdoor sensor is connected to terminals 5 and
6 “Outdoor Sensor”, the boiler will adjust the target
space heating set point supply water temperature
downwards as the outdoor air temperature increases.
If used, this sensor should be located on the outside
of the structure in an area where it will sense the
average air temperature around the house. Avoid
placing this sensor in areas where it may be covered
with ice or snow. Locations where the sensor will
pick up direct radiation from the sun should also
be avoided. Avoid placing the sensor near potential
sources of electrical noise such as transformers,
power lines, and fluorescent lighting. Wire the
sensor to the boiler using 22 gauge or larger wire.
As with the sensor, the sensor wiring should be
routed away from sources of electrical noise. Where
it is impossible to avoid such noise sources, wire
the sensor using a 2 conductor, UL Type CM, AWM
Style 2092, 300Volt 60°C shielded cable. Connect
one end of the shielding on this cable to ground.
Warning
When making low voltage connections, make
sure that no external power source is present
in the thermostat or limit circuits. if such a
power source is present, it could destroy the
boiler’s Microprocessor Control (Sage2.1). One
example of an external power source that could
be inadvertently connected to the low voltage
connections is a transformer in old thermostat
wiring.
D.
Power Requirements
Nominal boilers current draw is provided in Table
23. These values are for planning purposes only
and represent only the boiler’s power consumption.
To obtain total system power consumption add any
selected circulator and component current draws.
Viii. Electrical
(continued)
Model number
nominal Current
(amps)
APX399
<7
APX500
<6
APX800
<8
Table 23: Boiler Current Draw
E.
Multiple Boiler Wiring
Install over-current protection in accordance with
authority having jurisdiction or, in the absence of such
requirements, follow the National Electric Code, NFPA
70, and/or CSA C22.1 Electrical Code. Do not provide
over-current protection greater than 15 amperes. If it
becomes necessary to provide greater amperes (because
of the number of boilers provided) use separate circuits
and over-current protection for additional boilers.
F.
External
Multiple Boiler Control System
As an alternate to the Sage2.1 Control internal sequencer,
the Sage2.1 Control also accepts an input from an
external sequencer. Follow multiple boiler control system
manufacturer (Honeywell, Tekmar, etc.) instructions
to properly apply amultiple boiler control system. The
Tekmar Model 264 and Model 265 based control wiring
diagrams (Figures 44A and 44B) are provided as examples
of typical multiple boiler control systems.
Summary of Contents for Apex APX399
Page 65: ...65 VIII Electrical continued Figure 43 Ladder Diagram ...
Page 66: ...66 VIII Electrical continued ...
Page 67: ...67 Figure 44 Wiring Connections Diagram VIII Electrical continued ...
Page 110: ...110 1P 3 1P 2 1P 1 XIII Repair Parts continued 1C 1D 1E ...
Page 116: ...116 XIII Repair Parts continued ...
Page 118: ...118 XIII Repair Parts continued ...
Page 129: ...129 SERVICE RECORD DATE SERVICE PERFORMED ...
Page 130: ...130 SERVICE RECORD DATE SERVICE PERFORMED ...
