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SECTION 2
EXE-IOM-230112
3. See the Operation section for programming DHW
priority. Refer to the Hydronic PURE Control™ User
Manual for complete instructions.
4. When extending the wire lead, use 18 to 22awg twisted
2 conductor stranded copper with insulated jacket.
Ensure connections are tight with no shorts. Soldered
and heat shrink tubing connections are recommended.
Never use wire nuts to join lead to extension.
5. For complete instructions, refer to the Technical
Data sheet for the domestic hot water sensor prior to
installation.
` MOTORIZED ISOLATION VALVE CONTROL
1. A contact is provided in the boiler control panel to
operate a two-position motorized isolation valve.
Contacts are rated for up to 7.4A at 120V. The valve type
may be either power-open / power-close, power-open /
spring-close, or spring-open / power-close. Depending
on valve actuator type, a control relay may be required
(not provided). Do not power the actuator using the
boiler control power supplies.
2. Select a valve actuator with a cycle time from close
to open, and open to close, of 45 seconds or less. Do
not use slower valve actuators as they may result in
system issues such as manual reset lockouts or poor
temperature control response.
3. A motorized isolation valve is used in variable primary
piping arrangements, in accordance with ASHRAE
90.1-2013, to prevent flow from traveling through idle
boilers.
4. The lead boiler motorized isolation valve must be field
programmed to remain open when all boilers are idle
to provide a path of flow in the hydronic system. See
the Operation section for programming motorized
isolation valve control. Refer to the Hydronic PURE
Control™ User Manual for complete instructions.
` AUXILIARY SAFETY INTERLOCK FOR EXTERNAL DEVICE
1. When the boiler receives a call for heat, the startup
sequence checks the safety device limit string to the
J5.1 terminal which includes the interlock contact.
2. Where used, the external device must close the
interlock contact within 60 seconds of a call for heat or
the boiler will enter an safety shutdown alarm state. An
actuator with maximum 45 second speed or shorter is
recommended. Ensure appropriate actuator selection
to satisfy this timing requirement.
3. A jumper is factory installed in the interlock circuit. For
Questions? Please Contact Your Local Manufacturer's Representative
applications requiring a safety interlock, this jumper
may be removed with terminals wired into the dry
contacts of an external device.
4. The interlock contacts provide a 24 VAC signal. Do not
apply an external power source to the interlock
contacts; wire only to dry contacts.
5. Typical uses for the safety interlock include but are not
limited to: motorized isolation valve end switches, proof
of exhaust draft assist fan operation, motorized air
intake louvers.
6. Multiple safety interlocks may be used, wired in series.
` SYSTEM PUMP CONTROL
1. The boiler controller provides start/stop for one system
(secondary) pump. Do not power the pump directly
through the boiler panel.
2. The pump start/stop contacts has a maximum rating of
7.4 Amps at 120 VAC.
` DEDICATED BOILER PUMP CONTROL
1. Some installations may utilize primary-secondary
piping arrangements instead of variable primary piping
arrangements. In these instances, the boiler (primary)
loop is decoupled from the system (secondary) loop,
and a dedicated boiler pump will be required to provide
flow through the boiler.
2. The boiler controller provides a dedicated boiler pump
start/stop signal only; the pump cannot be powered
through the boiler panel. An external motor starter
or variable speed drive (not provided) is required to
control the circulator pump.
3. The pump contact has a maximum rating of 7.4 Amps
at 120 VAC.
4. Can be modulated by the boiler controller using the
4-20mA output provided. A signal converter (not
provided) will be required for pump controls requiring a
0-10VDC signal.
INSTALLATION
2-39
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