Periphery - Buderus Logamax plus GB162 Applications Manual

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2.1 Periphery

2.1.1 Low Water Cut-off (LWCO) and External Manual Reset High Limit
National or local code may require the installation of an external
Low Water Cut-Off (LWCO) and/or an External Manual Reset
High Limit.
Notes:
1. Contractor to furnish and install LWCO and Manual Reset
High Limit devices as required by local codes.
2. Do not install any type of valve or check valve in between
boiler and LWCO or Manual Reset High Limit.
3. Refer to the manufacturer's instructions when installing
LWCO and Manual Reset High Limit.
4. LWCO is installed external to the boiler and must
be located above the highest point of the boiler heat
exchanger.
5. Manual Reset High Limit remote sensing bulb must be
located in the boiler supply.
6. In a cascade each boiler must be equipped with its own
LWCO and Manual Reset High Limit.
Fig. 1 Low Water Cutoff views
NOTE: Power supply to LWCO and external high limit not shown for
Technical specifi cations are subject to change without prior notice
Installation instructions (Fig. 1):
At the back of the boiler manifold remove the 1" plug and
connect a 1" Tee. At the horizontal end connect a 1" well for
the Manual Reset High Limit probe. At the vertical connector
of the Tee, install a 1" stand pipe that reaches above the
highest point of the boiler heat exchanger. Install a second
Tee with an automatic air vent at the top and a LWCO just
below.
Wire the LWCO and the Manual Reset High Limit normally
closed dry contacts in series with EV pins 1 and 2 on the
boiler, which will shut off the burner when the connection is
interrupted.
clarity. Follow manufacturer's instructions.
GB162 Applications Manual
Logamax plus GB162 applications manual | 03.2013