Siemens SED2 VFD Electronic Bypass Option 125-3208 User Manual

30 

 

Siemens Building Technologies, Inc. 

 

P1121 

 

0s to 650s 

1. Press   to advance to 

parameter P1121. 

2. Press   to access the 

parameter values level. 

3. Press   to advance it desired 

value. 

4. Press   to confirm and save 

the setting. 

Site Setting 

Default = 30 

Typical fan = 
120s 

Typical pump = 
30s 

 

1.  Setting the ramp-up time too short can cause the SED2 to trip (F0001 over current, F0002 over voltage, 

or F0003 under voltage.  

2.  If using an external frequency setpoint with set ramp rates (such as from a PLC), achieve optimum 

SED2 performance by setting ramp times (P1120 and P1121) slightly shorter than those of the PLC.

 

P3900 

 

0 = End without motor calculation 
or factory reset. 

1 = End with motor calculation 
and factory reset (recommended 
on SED2 without bypass option). 

2 = End with motor calculation 
and with I/O reset. 

3 = End with motor calculation 
but without I/O reset 
(recommended with SED2 with 
bypass option). 

1. Press   to advance to 

parameter P3900. 

2. Press   to access the 

parameter values level. 

3. Press   to advance to 1. 

4. Press   to confirm the 

setting. 

Setting = 1 

Default = 0 

 

1.  P0010 must always be set back to 0 before operating the motor. 

2.  If P3900 is greater than 0 on completion of commissioning, P0010 is automatically set back to 0. 

3.  If P0700 either indeed was changed during this process, programming of P0704 = 3 is required.