Cascade Instructions
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Tx I&O Manual
50
Labeling
- Label all wires prior to disconnecting them when servicing controls. Wiring
errors can cause improper and dangerous operation. Failure to follow instructions may
result in property damage or personal injury.
Continuity
- Before connecting the line voltage wiring, perform a continuity check
between all wires and ground to make sure that there are no electrical leaks that could
blow a fuse or damage electrical components. Also check the polarity of the line and
neutral wires. Line must measure 120VAC to ground; neutral must measure zero.
Failure to follow instructions may damage the unit.
Max Load
– The total load rating of circulators powered by outputs BOILER PUMP and
CH PUMP, or BOILER PUMP and DHW PUMP cannot exceed 2.6 Amps.
Table 12-1 Field Connections
Connection
Location
Description
ARGUS LINK –
1
Argus Link Communication
– used to cascade up to 16 boilers, also for connection to
USB interface for PC-connection and BMS Modbus/Expansion Interface Module.
ARGUS LINK
+
2
SENSO
R
COMMON
3
Sensor Common
– Common port for field inputs SYSTEM, OUTDOOR and DHW.
SYSTEM
4
System Temperature Sensor (Manditory for Cascade)
– Wire to terminals 3 and 4 of the
Manager boiler in a
cascade
. Sensor would be installed on the system supply pipe feeding
the Central Heating system to allow accurate control of system temperature. Sensor is
available from NTI, P/N: 84010.
OUTDOOR
5
Outdoor Temperature Sensor
–
A wall mountable OD Sensor is included with each
boiler; connect to terminals 3 and 5. In a cascade, the OD Sensor only needs to be
connected to the main boiler. The use of the OD Sensor is required to allow the boiler
control to automatically infer the heat load of a central heating system.
DHW
6
Tank Thermostat / Sensor (
Not Applicable for Tx-Combi models) – Connect the contacts
of a DHW Tank Thermostat, or leads of an approved DHW Tank Sensor (NTI P/N:
84632), to terminals 3 and 6. When using a Thermostat, set DHW mode = 2 (menu setting
2-08). When using a Sensor, set DHW mode = 1. See Section 17.0 for more details.
THERMOSTAT
7
24VAC Room Thermostat Input
– Connect central heat demand switch (room
thermostats or zone control end switch),
or
“nighttime setback” / “time of day” switch to
terminals 7 and 8. Switch must be an isolated end switch.
8
DHW PUMP
9
120VAC output to the DHW circulator; powered during a demand for DHW. Total load of
DHW PUMP and BOILER PUMP must not exceed 2.6Amps. Not applicable for Tx-
Combi models.
CH PUMP
10
120VAC output to the Central Heating circulator; powered during a demand for Central
Heat. Total load of CH PUMP and BOILER PUMP must not exceed 2.6Amps.
BOILER PUMP
11
120VAC output to the main boiler circulator; powered during all demands. Total load of
BOILER PUMP and CH PUMP (or DHW PUMP) must not exceed 2.6Amps. Not
applicable to Tx-Combi models – pump is factory wired.
L2 NEUTRAL
12
Location for connecting neutral of the power supply and all circulators.
13
L1 120VAC
14
Location for connecting line voltage of the power supply. Note; most installation codes
require the installation of a service switch to break line voltage to the appliance.
Ground
Green
Wire
Location for connecting earth ground and for grounding all circulators.
Safety Circuit
Purple
Wire
120VAC Safety Limit Circuit
– Purple wire located in junction box; line can be cut and
connected to optional external limits, i.e. LWCO.
