Electric boilers series SB, 375 - 600 kW

SB 375 - 600 kW

The larger series of Varmeteknikk's ridgid and reliable element boilers

350-600 kW are delivered for 3-phase power connection in 3x400 V or 3x690 V, and 450-600 kW in 3x230 V (other boiler dimensions). Other voltages may be delivered on request.

The regulator/controller is very user friendly, and regulates the power in 30 steps.

An optional outdoor sensor is avalable for optimized economical operation. The boiler output temperature is then compensated for the outdoor teperature according to a heat curve.

The boilers have digital and analogue in- and outputs for external control an monitoring, so that they may be visulized and controllerfrom the customers SCADA system. Optionally bus couplers may be delivered preinstalled for MODbus or BACnet communication.
The boilers may normally also be controlled directly from a heat pump.

Varmeteknikk boilers are delivered with standard DN125 - PN16 flanges.



Varmeteknikk AS panel til en av elektrokjelene

Design data

Design pressure6 bar
Design temperature110 °C
Max operational temperature100 °C
Water volume310 l
Min. flow1,3 l/s,  4,7 m3/h
Max flow21 l/s,  75 m3/h

Hydraulic connection

Connetion typeFlange DN125 - PN16
Connection sideRear
Drain and expansion/ventG 2"


Temperature range5 - 100 °C
Regulation steps30
Steptime up1-250 s
Steptime down1-20 s
Regulation typePI 


The boilers may also be delivered with connection box on left side.

This series may also be delivered in a 16 bar version.


230 V versions of the 450-600 kW boilers are delivered with side connection and two connection boxes.
See info for the larger models SB 450 - 1200 kW.

Power connection

No. of connection boxes1
Connection sideRight (standard)
Left (optional)
No. of cables each box4
No. of terminals each phase4
Cable cross section35 - 240 mm2
Max terminal current

380 A Al - 425 A Cu



Control voltage

Voltage230 Vac - 50 Hz
Amperage10 A
Internal fuseØ5x20 mm, 10 A


Signals for external control


Control signals 
Start/stopExternal potential free closing contact
Temp. setpoint0-10 Vdc = 0-100 °C
Max step/power0-10 Vdc = 0-30 steps
OperationInternal potential free closing contact
AlarmInternal potential free changeover contact
Setpoint0-10 Vdc = 0-100 °C
Temp.0-10 Vdc = 0-100 °C
Step/power0-10 Vdc = 0-30 steps

SB2375-2400, SB4375-4600, SB6375-6600


All dimensions in mm.

Technical data

TypeNRF no.Power

3 x 230 V

Current (A)

3 x 400 V

Current (A)

3 x 690 V
Current (A)
Net weight
SB 23758205361375941--450
SB 240082053624001004--450
SB 43758205373450-541-450
SB 44008205374400-577-450
SB 44508205375450-650-450
SB 45008205376500-722-450
SB 46008205377600-866-450
SB 63758205391375--314450
SB 64008205392400--335450
SB 64508205393450--377450
SB 65008205394500--418450
SB 66008205395600--502450


Outdoor sensor

Outdoor sensor for temperature compensated heatcurve regulation.
Dim. 60x60x30 mm.
Connection 2-core min. 0,5 mm2. Max length 50 m.


Transfers all the standard digital and analoug signals to desired protocol MODbus TCP, MODbus RTU (RS485) or BACnet IP (different bus couplers).