Description
Product Introduction
The RELIANCE SS4437 is a regenerative converter from the SS4000 series. It manages DC bus voltage while returning braking energy from connected inverters back to the AC supply.
Traditional braking resistors waste that energy as heat. This unit pushes it back onto the line — continuous regeneration, not pulsed. Input power factor stays at 0.95 or higher thanks to full phase synchronization with the PWM waveform. That matters when your facility meters reactive power.
Installation & Configuration Guide
Phase 1 — Pre-Installation (est. 20 min)
De-energize the main disconnect and verify zero voltage at the DC bus terminals with a Fluke 115. Wait 5 minutes for capacitor discharge. Photograph terminal connections and DIP/jumper settings. Record the model number and any revision suffix — SS4437 and SS4437P differ in parallel configuration capability.
Phase 2 — Removal (est. 10 min)
Label all power cables: L1/L2/L3 input, P/N DC bus, G ground. Note the reactor connections and precharge resistor jumper positions (PR1, PR2, PR3). Release mounting bolts and slide the chassis out. Inspect the DC bus capacitor tops for bulging — a common aging failure.
Phase 3 — Installation (est. 10 min)
Confirm the replacement matches your original model (SS4437 vs. SS4437P). Mount the chassis in the cabinet. Reconnect power cables per photos. Verify precharge resistor configuration: for built-in resistor, jumper PR2–PR3 and open PR1. Connect the main magnetic contactor control terminals (MC1, MC2).
Phase 4 — Power-On & Testing (est. 15 min)
Energize control power first. Observe the seven-segment LED display for fault codes. Apply main power and verify DC bus voltage climbs to the setpoint (typically 700 V for 460 V input). Run the connected inverter under load and confirm regeneration current flows back to the AC line. Monitor input current waveform for excessive harmonics.
Troubleshooting Quick-Reference:
- No DC bus voltage → check main contactor operation, reactor connections
- Overvoltage fault → verify DC bus setpoint parameter matches inverter requirements
- Phase loss fault → check input fuses and disconnect
- ❗ Parallel configuration mismatch → B40826311XXX parts cannot be paralleled with SS4437A units
- Regeneration not working → check RUN sequence signal and main magnetic contactor answer-back
Can I just drop this in and go?
No. The SS4437 is a discontinued chassis-mount unit with specific peripheral requirements. You need reactors on each input phase (not three-phase reactors — single-phase per leg), a main magnetic contactor, and proper precharge resistor configuration. Install it without those and you risk damage on first power-up.
My system uses SS4437P units in parallel — can I mix with this?
Case-by-case, and the answer is usually no. Reliance documentation states B40826311XXX parts cannot be used together in a parallel configuration with SS4437A units . If you’re replacing one unit in a parallel bank, match the exact model suffix and part number.
