Intellitec 50 Amp Transfer Relay Delay - Dual Input Genset
Service Manual
How It Works
The 50 Amp Transfer Relay is used to transfer the power source of a coach between the shore power and the generator. Power from the shore power cord is fed to the normally closed contacts of two contactors. This allows the power from both lines of the shore cord to pass through into the coach distribution panel.
Power from the generator is fed to the normally open contacts and to a delay circuit on the printed circuit board. When the power from the generator is applied, the delay circuit senses the power from Line 1 and applies DC power to the contactor coils, after approximately 15 seconds. This pulls in the two contactors, applying the power from the generator to the coach.
Typical connections for 50 Amp service are shown in Figure 3.
The unit can also be wired to act as a transfer between both lines of a 5.5 KW or 6.5 KW generator and a 30 Amp shore power cord. The connection diagram for this unit is shown in Figure 4.
Servicing
There are no dealer serviceable parts in this box. Replacement of a defective box is the only way to correct a failed unit.
CAUTION
To gain access to the connections:
BEFORE ATTEMPTING TO REMOVE THE COVER, BE SURE THE POWER FROM BOTH THE SHORE CORD AND GENERATOR ARE OFF. Remove the two hex head screws at either side of the row of connectors. Pull the cover forward and lifting up, remove the cover to expose the interior of the unit. All servicing within this box should be done only by a qualified Service Technician.
Removal and Replacement
IMPORTANT: Remove the cover to gain access to the connections. Make a diagram of all the connections before removing any wires.
First, unscrew the six cable clamp screws releasing the cables, then loosen the set screws of the 12 connectors along the field wiring side of the terminal blocks, in order. This will allow the cables to be removed. (Unscrew the four mounting screws and remove the unit from the coach.)
IMPORTANT!
During installation, wire per the wiring diagram and instructions printed on the box cover. The field wiring screws must be tightened to 35 in-lbs to insure a tight connection.
Diagrams and Connections
Figure 1: Cover Removed (Inside View)
This figure shows the internal components of the transfer relay with the cover removed. It illustrates the terminal blocks labeled 'FROM GENSET', 'FROM SHORE POWER', and 'TO COACH PANEL', each with connections for GND, LINE1, NEUT, and LINE2.
Figure 2: Equivalent Circuit
This diagram illustrates the equivalent electrical circuit of the transfer relay. It shows the 'RELAY DRIVE & DELAY ELECTRONICS' connected to various input and output terminals, including Chassis Ground, Generator Line 1, Generator Neutral, Generator Line 2, Shore Line 1, Shore Neutral, Shore Line 2, Panel Line 1, Panel Neutral, and Panel Line 2.
Figure 3: Typical 50 Amp Service Connections
This diagram shows the typical wiring connections for a 50 Amp service. It depicts the Generator, Shore Cord, and Main Breaker Panel, with the transfer relay connecting them. Connections are made to terminals for Ground, Line 1, Neutral, and Line 2 for both the generator and shore power, and to the coach panel.
Figure 4: Typical 30 Amp Service Connections
This diagram illustrates the typical wiring connections for a 30 Amp service. It shows the Generator, Shore Cord, and Main Breaker Panel, with the transfer relay connecting them. Connections are made to terminals for Ground, Line 1, Neutral, and Line 2 for both the generator and shore power, and to the coach panel. This configuration is for a 5.5 KW or 6.5 KW generator.
Troubleshooting
No power to the coach from shore cord.
- Check to be sure shore outlet has power.
- Reset shore circuit breakers to be sure.
- Measure the voltage from Line 1 to Neutral at the Transfer Relay terminals.
- Check the circuit breakers in the coach distribution box to be sure they are not tripped. Reset them to be sure.
- Replace Transfer relay.
No power from generator.
- Check to be sure generator has power. Reset the generator circuit breakers to be sure.
- Measure the voltage from Line 1 to Neutral at the Transfer Relay terminals.
- Check the circuit breakers in the coach distribution box to be sure they are not tripped. Reset them to be sure.
- Replace Transfer relay.
