What are the differences between an ATS46 and an ATS48 Soft Starter?


27 November 2023

Differences to consider when retrofitting an ATS48 in place of an ATS46.

Product Line:
Altistart ATS46 and ATS48


Application differences between the ATS46 and ATS48 soft starters.

The programming and the dimensions will be different. In most cases the ATS48 is smaller than the equivalent ATS46. Please refer to the Instruction Bulletins referenced in this document.

Control voltage differences
ATS46 used a multitap CPT accepting control voltage up to 500Vac
ATS48 does not have an internal CPT and will only accept control voltage between 90Vac and 270Vac. 
If existing control voltage is over 240Vac, an external control transformer may be required to step down the voltage to an acceptable range.
The control power burden varies with ATS48 size:
ATS48D17Y and ATS48D22Y require 25 Watts.
ATS48D32Y, ATS48D38Y, ATS48D47Y, ATS48D62Y, ATS48D75Y, ATS48D88Y, ATS48C11Y, ATS48C14Y, and ATS48C17Y require 30 Watts.
ATS48C21Y, ATS48C25Y, and ATS48C32Y require 50 Watts
ATS48C41Y, ATS48C48Y, ATS48C59Y, ATS48C66Y, ATS48C79Y, ATS48M10Y and ATS48M12Y require 80 Watts.

Fault relays
ATS46 had a Fault Relay with both NO and NC contacts (NO terminals are R1A and R1C. NC terminals are R1B and R1D).
ATS48 only has 1 NO fault relay, R1A-R1C.
If existing control wiring used the NC R1B-R1D, then add an interposing relay controlled by the R1A-R1C relay to keep that functionality.

Power Terminals for the optional shorting contactor
ATS46 had 6 terminals for the optional Shorting contactor: A1 B1 C1 and A2 B2 C2
ATS48 only has 3 terminals: A2 B2 C2
The ATS48 L1, L2, L3 terminals are for incoming 3-phase line power connections. This may require that separate terminal blocks be used to connect the line side of the shorting (bypass) contactor. Consider adding a power terminal block to split the power circuit to feed both the ATS48 L1L2L3 terminals and line side terminals L1L2L3 of the shorting contactor.

In some cases as described above you may need add several components to make the conversion work.
1: Step down control power transformer
2: Interposing control relay
3: Power terminal block
Refer to the attached ATS46 manual VD0C32S301B
Refer to the attached ATS48 manual S1A37491