Installation Manual

Installation

1–40 975-0639-01-01 Rev D

This guide for use by qualified personnel only

Restrictions on Motor Size

An appliance may require three to six times its normal running current in order to

start. The Conext SW can handle surges up to twice its rated amount (surge

current) for five seconds. For example, the model Conext SW 4024 120/240 is

rated as having a maximum continuous output current of 15 amps

and a surge

capability of 32 amps. In motors, the locked rotor amp (also called its starting

current) may be specified on the motor nameplate as “LRA” or “LRI”. The LRA

must not exceed the surge current rating of 32 amps.

When considering appliances with large motors, follow these guidelines:

• Make sure that the motor’s LRA rating is no more than surge current amps.

The Conext SW may not be able to start a motor with a higher LRA, and the

Conext SW will shut down if the attempt is made.

• Make sure the battery bank, DC cables and DC fuses are capable of

handling up to 600 amps DC for five seconds. A weaker circuit may not be

able to provide sufficient power to the Conext SW to allow the Conext SW to

start up the appliance. Again, if the circuit cannot deliver the required

current, the system may shut down or the fuse may open.

Table 1-5 Battery Sizing Worksheet

Appliance

(A) Power

Consumption (Watts)

(B) Operating Time per

Day (Hours)

Daily watt-hours

needed for this

appliance

(= A × B)

W hours Wh

Total daily watt-hours of AC load Wh

× Number of days between charges

= Total watt-hours of AC load between charges Wh

Battery Ah used between charges (divide by 20 for 24 volt system) Ah

Recommended Battery Bank Size in Ah (multiply by 2) Ah

ConextSW-NA-InstallationGuide.book Page 40 Tuesday, July 21, 2015 4:39 PM