45
110332-04 - 2/23
PHTM II
Installation, Operating & Service Instructions
Figure 12-4: Boiler-to-Boiler Connections
X4
X5
X6
BCC
X2
Fuses
X1
X3
XB-2
XB-1
RJ45 Connections (2)
12
Field Wiring
(continued)
2. External power must not be applied to any low
voltage terminals - doing so may damage boiler
control. Note following:
A. Heat T'Stat (field supplied) - Connect room
thermostat or zone panel end switch (isolated
contact only) to "Heat T'stat" terminals.
B. Aux T'Stat - Auxiliary T'Stat can be used
for 2nd zone or indirect demand. Refer to
Table 15-13 for explanation.
C. External Limit: External limit terminals are
intended for use with field supplied safety
device, such as a manual reset high limit or
LWCO. When an external limit is used,
jumper between these two terminals must be
removed.
D. Outdoor Sensor - Use only Tasseron TSA00AA
(P/N 108681-01) 10k outdoor sensor. When
optional sensor is connected, boiler
control will provide outdoor air sensor based
freeze protection interlocks. When placing
sensor, consider following:
i. Locate sensor on outside of building.
ii. Avoid placing sensor in areas where it may
be covered with ice or snow.
iii. Avoid direct radiation from sun.
iv. Avoid placing sensor near potential
sources of electrical noise such as
transformers, power lines, and fluorescent
lighting.
v. Wire sensor to boiler using minimum 22
AWG wire.
vi. Where electrical noise sources cannot be
avoided, wire sensor using 2 conductor,
UL Type CM, AWM Style 2092 shielded
cable. Connect one end of shielding on
this cable to ground.
E. Header Temperature Sensor - Use only
Honeywell 32003971-003 (P/N 108703-01)
sensor. Optional header sensor is required
to enable Lead/Lag sequencer. Locate
sensor as shown in Figures 10-3 and 10-4.
Wire sensor using a 2 conductor, UL
Type CM, AWM Style 2092, 300 Volt 60°C
shielded cable. Connect one end of shielding
on this cable to ground.
F. LWCO wiring - Although not necessary to
protect this boiler, some jurisdictions may
require installation of LWCO with
this boiler.
i. Refer to Section 10 Heating System Piping
for LWCO kits available from manufacturer.
ii. LWCO from these kits is installed to
4 pin connector on Low Voltage
Connections terminal strip.
G. RJ45 Connections - Boiler-to-Boiler
communication network is used for multiple
boiler ("Lead-Lag") installations.
Note: Combi boilers may only be used as
slaves in such a system. Refer to Table 15-16
for information on enabling this feature.
Boiler lead/lag sequencer connection is made
directly to control. Refer to Figure 12-4.
