Crown Boiler Phantom X series, Installation And Operating Instructions Manual, Page: 60 / 136

60
Figure 39: Low Voltage Field Wiring
3. 24VAC low voltage connections
are located on
left side of right PCB and are shown in Figure 39.
One 24V fuse and spare are provided. PHNTM399C
and PHNTM500C use 1.6A slow-blow fuse.
4. 5VDC low voltage connections
are located on
right side of right PCB and are shown in Figure 38.
5. If the outdoor sensor is connected
, 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, 300 Volt 60°C
shielded cable. Connect one end of the shielding on
this cable to ground.
VIII. Electrical
(continued)
NOTICE
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. One example
of an external power source that could be
inadvertently connected to the low voltage
connections is a transformer in old thermostat
wiring.
E. Flow Switch Wiring
Phantom X boilers require a flow switch to prevent boiler
overheating. See Section VI, Water Piping and Trim, and
flow switch instruction sheet for piping details. The flow
switch and flow switch wire harness are factory provided.
1. Wire flow switch harness to boiler.
Connect
Molex on harness to boiler low voltage connector
P11, labeled “Flow Switch”.
2. Wire flow switch harness to flow switch.
Connect fork terminals on harness to flow switch
NO (normally open) and COM (common) terminal
screws.
NOTICE
Disable boiler internal sequencer when connecting to an energy managment system.
OR
SIZE 399-525: 1.6A SLOW BLOW
SIZE 600-825: 2.0A FAST ACTING
5mm X 20mm FUSE
OR
(+)
(-)
SPACE HEATING
THERMOSTAT
OPTIONAL
DOMESTIC HOT WATER
THERMOSTAT (IF USED)
DAMPER PROVING
SWITCH (IF USING
ROOM AIR)
OPTIONAL MANUAL RESET
EXTERNAL LIMIT(S)
ALARM CONTACTS
OPTIONAL ENVIRACOM
THERMOSTAT OR
ZONE PANEL
FLOW
SWITCH
OPTIONAL
24V LWCO
OPTIONAL
OUTDOOR
SENSOR
OPTIONAL
HEADER SENSOR
OPTIONAL
DOMESTIC HOT
WATER SENSOR
OPTIONAL
MULTIPLE BOILER
COMMUNICATION
OPTIONAL
ENERGY
MANAGEMENT
SYSTEM
OR
OR
OPTIONAL AUTO
RESET EXTERNAL
LIMIT(S)
SIZE 399-500: 1.6A SLOW BLOW
DHW HEAT SOURCE
SENSOR*
* NOT for direct measurement of DHW
temperature. (See page 101)
WARNING
Scald Hazard. The DHW sensor connection on this boiler is intended for use in modulating the boiler supply
temperature at the indirect water heater. It is not intended for direct control of DHW temperature. Attempting
to use this sensor for direct control of DHW temperature could result in injury or death due to scalding.