09/17/2014
1
BI308
GENERAL
The basic
components
for an electric energy heating system typically include:
1.
Electric Mini-Boiler itself – covered by this manual.
2.
Thermostat hookup control – covered by this manual.
3.
Plumbing kit or piping material at the boiler itself – can be ordered as a kit, reference catalog number
EMB-PK.
a.
These items are shown on plumbing installation drawing BX305.
4.
Circulating pump – typically sized for head pressure and system flow requirement, typical catalog
number EMB-P2.
5.
Radiant heat devices/components.
APPROVED TUBING/PIPING
When plumbing this boiler and its peripheral parts to the radiant floor loop system, all plumbing parts and/or
tubing must be sealed to prevent entrance of oxygen.
Use only tubing or polyethylene tubing with oxygen Diffusion Barrier (ie. PEX).
SYSTEM OR WATER FLOW
In order to prevent hi-limiting and assure full 20+ years parts life, the piping system/basic plumbing/circulator
pump must be arranged to provide flow greater than minimum GPM shown in Table 1. If zoned system, this
applies when the smallest zone is operating.
TABLE 1 - ELECTRO-BOILER SPECIFICATION
240 volts, 60 Hz, single phase
Model
Btuh
Rating
Amp
Stages
Min. GPM for 160° F
and above*
Min. GPM for 144° F
and below
EMB-H-5 15,000 5
kW 18.7A
1
1
.5
EMB-H-7 24,000 7
kW 29.1A
2
1
.5
EMB-H-9 31,000 9
kW 37.5A
2
1
.5
*Note: If less than 1 GPM is possible in high temp. mode, suggest using primary/secondary piping to increase
flow rate through boiler, or consider installing zone controller EB-5415A (see page 2 for details).
MULTIPLE ZONES AND RADIANT TEMPERATURES
Same water temperature all zones –
in this case the system can be setup as one pump with the water circulated
through the boiler and directly to a manifold containing the various zone valves. Although this model series has
a built-in outlet sensing and controller mechanism for staging the elements, also consider the next section, Zone
Controller. If not using zone controller, the end switches of all of the zone valves are paralleled and directly
control R and W to turn on the boiler.
Various water temperature requirements –
if this is the case, a primary loop with mixing valve for the
various zone temperature requirements is necessary. Injection pump techniques can also be used. However,
usually injection pump techniques come with a controller which is designed to protect a gas boiler from cool
water return. This is simply not needed and a duplication with the temp. sensing controller within this Electro-
boiler and the injection pump controller will be of no benefit within the operating system. The zone valve/zone
pump control strategy must be wired to provide the boiler “R and W” contact closure and the primary pump is
connected to the boiler pump contacts. This assures the primary pump is active and running whenever the boiler
is turned on via contact closure on “R and W”. At least one zone must be open before turning on the primary
pump/Electro-Boiler. Do not design a system where the Electro-Boiler is supposed to operate as a “hot boiler”
based upon its outlet sensor without the primary pump circulating water, minimum .5 GPM is required.
