Room Thermostat Placement; Two-Temperature Operation Or Feature - Electro Industries EB-MO-10 Installation & Operating Instructions Manual

capacity, the zone controller "smarts" only allows the appropriate boiler stage which can handle that capacity.
Also this is additive if more than one zone calls at any one time – order EB-ZEA-1.
3. Two temperature system with unbalanced zones – if the application includes zone one requiring high
temperature (fin tube, air handler, etc.) and the remaining zones are radiant floor low temperature, this zone
controller (EB-ZEA-1) will automatically raise the output of the high temperature zone. This is a priority
arrangement, zone 1 holds off the other zones while the high temperature output is heating. If at the end of the
high temperature zone there is a call on any of the low temperature zones (up to three plus slave 4), there will
be a pump only function until the outlet temperature drops below the front panel dial setting.
ZONE CIRCULATORS
The EE-5051 switching relay can be used to interface line voltage pumps with the boiler R and W control
terminals, see drawing BH008. However, when using zone controller EB-ZEA-1, these are not required.

ROOM THERMOSTAT PLACEMENT

Fin tube radiation, fan coil, etc. – heat only wall t-stat, connected to operate zone valves (see previous
section) or for single zone the t-stat is connected directly to Electro-Boiler R and W.
Floor radiant – comfort and proper space heating response is a direct relationship to the thermostat type
and the placement of the thermostat sensing bulb. Typically an under floor heating system can be broken
down into three categories.
A. Energy storage, water tubing is under the concrete or within the sand
base – the controlling thermostat must have a remote bulb, and this remote
bulb must sense the concrete slab temperature (slab stat). Coordinated with
the concrete pour, install a ¾" PVC, minimum bend radius of 7 inches, and
locate at approximately center (vertical) of the concrete slab. The thermostat
sensing bulb can later be pushed down this PVC conduit. If the slab is already
poured without conduit for slab stat, use electronic remote sensing thermostat
such as Electro Industries' ES-24-BR. These devices only require a ¼" hole
drilled in the floor at some convenient location (preferably off a center wall,
not within 2 feet of outside wall).
B. Floor covering, medium to high insulation – use slab stat as described in paragraph A above.
C. Quick response, hydronic tubing just under the concrete surface, no flooring material over the concrete
– in this case, heated water can directly radiate into the room, a standard wall mount room thermostat is
adequate. Mount room thermostat on an inside wall similar to most heating systems.

TWO-TEMPERATURE OPERATION OR FEATURE

When using Electro's zone controller in priority mode,
the boiler system can automatically raise the outlet
temperature with zone 1 calling. This is setup for
default of 150° or pulling a jumper peg the high
temperature value is 176°. See appropriate zone
controller installation manual for details.
10/22/2008
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