PPR-3T8 Overview

The "PPR3T8" is designed for use with motors which require protection against overload and underload conditions. The Avanti PPR3T8 provides detection of both these conditions and is particularly suitable for monitoring pump motors providing extra sensitive overload protection.

The unit is a normal plug-in module, simple to set up and incorporates the use of one 50 amp current transformer covering load currents from 1.0 amp to 18 amps. Higher load currents can be accommodated by using a larger current transformer with a 5 amp output.

(Line thru CTx once only – see diag 1.)

The unit has a built in fixed 5 second start-up delay and a fault latchout facility.

Description of Controls

1)         Calibration Screws (Potentiometers)

            “OCS”           Overload Current Setting screw                10-100%

            “UCS”           Underload Current Setting screw              10-100%

            “TDS”           Trip Delay Setting screw                            0-  10 seconds

2)         Six DIP Switches

             SW1              Underload restart timer selection

                                   ON (up) = minutes,  OFF (down) = hours

             SW2              Underload restart time

                                   ON (up) = 20min or 2 hours

             SW3              Underload restart time

                                   ON (up) = 40min or 4 hours

             SW4              Underload restart time

                                   ON (up) = 80min or 8 hours

             Note:  Use only one restart switch at a time. With all 3 switches OFF (down), the unit will operate without any underload restart timing (normal operation).

             SW5              2 position switch for 15% overload setting.

                                   ON (up) = 100% running current

                                   OFF (down) = plus 15% (115%) running current

             SW6              2 position switch positioned to suit motor size.

                                   See table for setting-up procedure.

3)         Indication Lights

            RED – top left              = Restart timing in progress (flashing)

            RED – top right            = Overload trip

            RED – Centre               = Underload trip

            GREEN – bottom         = Relay switched on.

 The "PPR3T8" offers a Phase Failure feature which is voltage & current dependant. (Maximum 15% above running current.) Trip delay is dependant on the response time setting: "TDS". The starter will not start unless all 3 phases are present on power up. The phase failure protection for running or power-up conditions will only operate if the unit is correctly installed. There is no visible indication for a phase failure condition. If tripped for any reason, a healthy incoming power supply should be confirmed first. Only on confirmation of all 3 phases being present should the over or under trip condition be investigated.

The PPR3T8 is designed in a manner that fine tuning of an overload condition is possible. Providing a discharge valve and ammeter is fitted, the overload setting and trip time combinations are extremely numerous, and easy to simulate.

PPR-3T8 Setting-up Procedure

 

1)         Establish full load current from the motor data plate.

 

2)         Ensure "SW5" is in "ON" position – This will be equal to 100% Running Current. (Lever in the UP position)

 

3)              Select Power Switch “SW6” position and pass “LIVE” through 50/5 Current Transformer as per table below.

                                     

Motor Current	“SW6” Position	Terminal no.	=	“LIVE” thru CTx	Diag. no.
1.1 amps TO   2.1 amps	1A-OFF	T3	=	3 Times	3
2.2 amps TO   3.9 amps	1A-OFF	T2	=	2 Times	2
4.0 amps TO   7.0 amps	1A-OFF	T1	=	1 Only	1
7.1 amps TO 14.0 amps	5A-ON	T3	=	3 Times	3
14.1 amps TO 18.0 amps	5A-ON	T2	=	2 Times	2

 

             The above table is for motors .37kW to 7.5kW. Larger motors of 11kW and above, any current transformer with a 5 amp secondary can be used.  Eg: 50/5 for 11kW and 18.5kW, 80/5 or 100/5 for 22kW and 30kW, etc. In these instances, pass “LIVE” thru CTx once only, and set “SW6” to 5A-ON.

4)         Turn overload screw "OCS" clockwise to 100% (Max)

            Turn underload screw "UCS" anti-clockwise to 10% (Min)

            Set response timer "TDS" to Maximum (10 seconds). Turn clockwise for maximum. This maximum setting is for the setting-up procedure only. After settings are completed, this timer setting must be set as low as possible – See Note (7)

5)         Overload Current Setting "OCS"

Start pump, check and ensure amps on all 3 phases are equal or below full load current. Wait 5 seconds and turn overload switch "SLOWLY" anti-clockwise until top red overload LED just comes on. After 10 seconds the unit will trip. Switch "SW5" to "OFF" position (shift lever DOWN). The overload is now set at 15% above the running current.

6)         Underload Current Setting "UCS"

Start pump and close discharge valve to simulate dry running (NO FLOW). Wait 5 seconds, then very "SLOWLY" turn the underload screw clockwise. The PPR3T8 underload red LED will come on and the unit will trip after 10 seconds. The unit is now set for dry running. To check this protection, reset the PPR3T8 (POWER OFF-ON), restart and run pump with open valve. After 5 seconds close the discharge valve. The unit must trip within 10 seconds after closure.

7)         Trip Delay Timer "TDS"

This timer setting applies to both over and underload condition. The timer can be set to suit the installation requirements. A short time will offer a more sensitive response to any possible fault conditions. Turn anti-clockwise for minimum.

IMPORTANT NOTE:   On borehole pumps, the response timer “TDS” should be set as short as possible. This short time will offer optimum protection during running and start-up.

                                        Continual resetting on an Overload or Underload trip will result in permanent motor damage.

Avanti PPR-3T8 Specifications

POWER:

400volt    50Hz    ±15%

POWER CONSUMPTION:

Approx. 6 V.A.

CONTACT RATING:

Trip: S.P.D.T.   5amp

Holding: S.P.S.T. n/o 5amp

SENSING CURRENT: 

1amp or 5 amp  (SW1)

START-UP DELAY:

Fixed 5 seconds

RESPONSE DELAY:

Adjustable 0-10 seconds (TDS)

ACCURACY:

1%

Revision 01/02/05