VOLTMAX ELECTRIC BOILER Installation and Operation Manual
(
Revised March 2019)
, Page
19.
ELECTRICAL CONNECTIONS
Wiring must conform to the National Electrical
Code and to state or local code requirements.
The electric boiler must be electrically grounded in
accordance with local codes, or, in the absence of
local codes, with the National Electrical Code.
MAIN ELECTRICAL SUPPLY
The power supply must be a 208 or 240-volt circuit
(single-phase or three-phase, 60Hz), 480 volts
(three-phase, 60 Hz) or 600 volts (three-phase, 60
Hz) protected by an appropriately sized breaker.
Refer to the boiler rating plate to select the breaker
capacity and wiring rating
Alimentation cables can be in copper or
aluminium.
The used cable gauge shall not be greater than the
maximum size allowed by the connection
terminals. See tables 1 through 6 for the specific
values.
PUMP SUPPLY
The VoltMax Electric boiler can control 1 or 2
pumps of the distribution system. According to the
VoltMax configuration, the contact of the pump will
function differently.
During a heat demand on W1 or W2, the contact
between
Pc
and
P1
or
Pc
and
P2
will be used to
start an external pump relay (maximum of 3
amps.). Depending on the configurations selected
in the controller, the pump P2 can have priority
over the pump P1.
N.B.
The VoltMax boiler is not designed to heat
without a water circulation in its tank. Therefore, if
external pump controls are used, they must be
interlocked with the operating authorization on W1
and/or W2 of the controller.
CONNECTION OF EXTERNAL
SIGNALS TO THE CONTROLLER
The connection of all external signals is made
directly on the boiler controller on terminals
located on top of it. See the connection diagram
on
Figure 8
Cables used for the connections shall resist
temperature up to 90 °C.
Connecting the building heat demand
signal or running authorization
Upon reception of a closed contact connected to
terminals
24V+
and
W1
or
W2
, the corresponding
circulating pump P1 or P2 will start and the boiler
will be allowed to operate.
If external controllers control the heating system
pumps, they must provide the operating
authorization signal. The boiler must not receive a
heat demand without the circulation pumps
running.
On heating systems when water circulation is
continuous, the heat demand control can be
connected in series with the pumps interlocks to
the
24V+
and
W1
terminals. The heating elements
will then be active and available only when there is
a request (dry contact).
If the heating system is designed to keep water
warm with continuous circulation, a dry contact
from the pumps relay or a contact from a flow
sensor must be connected on the
24V+
and
W1
terminals to maintain the boiler in demand as long
as the pumps are in function. The boiler will then
attempt to maintain the water temperature at the
set-point.
Operation with an upper fixed set-point W2 can be
established by connecting the auxiliary heating
demand signal (Dry contact) of a thermostat to the
24V+
and W2
of the terminal block.
In all operating modes of the controller, a heat
demand on W1 and W2/DHW (close contact) must
be present to DI1 or DI2 to allow the operation of
the boiler. The only exception is in domestic hot
water mode (DHW) with an indirect water heater
where the minimum boiler temperature shall be
maintained.
Connecting an auxiliary boiler
The boiler controller is designed to allow the
operation of a second boiler or an auxiliary boiler
according to two different mode of operation
“Auxiliary Backup” or Dual-Energy”.
To do so, connect the TT terminals of the auxiliary
boiler to terminals
AUX
of the VoltMax. The
maximum capacity of this contact is 3A/120Vac.
See section 4.3.4 for details.
