Page 3
36 & 54kW 3-Phase panel mount, heater controller
RE-PR3-E-36/54
Data Sheet Ref: 90501161
Issue: 5.2
International Tel: +44 1732 861225
UK Sales Tel: 0845 345 7253
International Fax: +44 1732 861226
UK Sales Fax: 0845 345 7353
www.sontay.com
Whilst every effort has been made to ensure the accuracy of this specification, Sontay cannot accept responsibility for damage, injury, loss or
expense resulting from errors or omissions. In the interest of technical improvement, this specification may be altered without notice.
90800066 Issue 1
Location & ventilation Back-up protection and load supply
The RE-PR3-E-xx power controllers are designed for mount-
ing on a vertical panel, with the heatsink fins to the bottom. It
is important that free air movement around the heatsink is
not restricted. Allow sufficient air space between adjacent
units to allow optimum performance of the heatsink.
The maximum ambient of 65°C should not be exceeded.
Where necessary control panels & enclosures should be
ventilated with a fan.
Load considerations
The RE-PR3-E-xx series of power controllers are designed
for resistive type loads only. Capacitive, or unusual heating
loads such as Molybdenum, Platinum or Tungsten, (which
can have a 10:1 hot to cold resistance ratio) are not suitable.
Over temperature monitoring
The RE-PR3-E-xx are fitted with a thermal protection device
to protect against over temperature. The unit will automati-
cally switch off the load in the event of the heatsink tempera-
ture exceeding safe limits (90°C ±1°C). Once the tempera-
ture has fallen to a safe level (85°C ±1°C) the load will be
switched on again if the supply is still present.
Under normal operating conditions the heatsink will not
reach 90°C but this might occur, for example when the ambi-
ent temperature exceeds 65°C.
Caution: During the course of normal operation metal parts,
in particular the heatsink, may get very hot.
Control supply
The RE-PR3-E-36 and RE-PR3-E-54 are factory set for a
internal 24V power supply.
If using an external 24Vac/dc supply you must change the
DIP switch SW4 on the PCB prior to applying power. This
is polarity independent.
Important! The external 24Vac/dc supply MUST NOT be
commonly linked to the control 0V signal terminal. Failure to
comply with this may result in the on board transformer over-
heating, the 1A fuses blowing and damage to the bridge
rectifier.
If there is a requirement for the alarm relay and LED to ener-
gise when any of the 3 phases fails, the external, isolated
24Vac/dc supply option must be used.
Earth connection
The RE MUST be earthed. A protective earth connection is
provided in the main terminal connections.
The RE-PR3-E-xx are protected by internal quick acting
semiconductor type fuses.
Load cables must be sized such that they are rated in ex-
cess of the fuse ratings.
It is recommended that a load break switch and a break
contactor is installed in the load supply. The supply to the
contactor coil should be interrupted by an over-temperature
thermostat located in the heater battery and also upon de-
tection of airflow loss.
Fault conditions
The factory default setting of DIP switch SW1 is the ON
position. In this position, the alarm relay will be energised
only when a fault condition occurs.
Changing SW1 to the OFF position will cause the alarm
relay to be energised continuously until a fault condition
occurs.
If the internal 24V supply is used, a fault condition will occur
on over temperature or if the L1 phase only is missing. If an
external 24V supply is used, a fault condition will occur on
over temperature, temperature sensor failure, or if any of the
3 phases are missing.
Should the 24V supply fail the output of the unit will fail to
OFF with no output.
Phase loss with auxiliary supply
When any one of the three phase inputs are missing, the
relay changes state and the LED flashes ON/OFF bursts of
1.5 seconds.
Note - This is only true when using an external 24V supply.
Alarm relay
The alarm relay has contacts rated up to 8A @ 230Vac
(RMS) load. Where the internal 24V supply is used, the relay
obtains its supply from the transformer via two 20mm 1A
fuses, and are connected to the L2 and L3 phases. There-
fore the alarm relay can only change state when there is an
over-temperature condition, a sensor fault, or if the L1 phase
only is missing.
Manual control
The units output can be controlled manually by using a 5kΩ
linear potentiometer connected as shown on page 4, with
the input signal set to 5Vdc (SW4).
Note: A 5kΩlinear potentiometer MUST NOT be connected
at same time as an external control signal.
