STP-301/451 Series Instruction Manual 
 
 
8-2
Operation 
Terminal Description 
 N.O
 NORM OUT
 N.C  COM
(13) (15)
(16)
 
Terminals for outputting the NORMAL OPERATION state 
signal. 
When the STP pump is in rated operation, the terminals 
between (16)-(13) are closed, and the terminals between 
(16)-(15) are opened. 
 
ACC
N.O  OUT
(17)
(18)
 
Terminals for outputting the ACCELERATION state signal. 
These terminals are closed when the STP pump is in 
acceleration. 
 
REMOTE
N.O  OUT
(19)
(20)
 
Terminals for outputting the STP pump REMOTE 
SELECTION state signal. 
When the MANUAL/REMOTE changeover switch on the STP 
front panel is set to ON (remote side), these terminals are 
closed (REMOTE operation). 
However, when the rotational speed is less than 20,000 rpm 
during power failure backup operation, this signal is not 
output. 
 
 (1) (3) (5) (7) (9)
(11) (13) (15) (17) (19) 
 
  (2) (4) (6) (8)
(10) (12) (14) (16) (18) (20) 
 
TB1 Terminal Arrangement