mylespetro
Member
Hey everyone,
Working on a project that uses an old Reliance GV3000 on an agitator, with the optional Remote Meter Interface (RMI) board for additional I/O. The equipment was bought second-hand and everything had been previously working as intended as far as I know.
EDIT: We followed the recommended capacitor reforming procedure, and the drive is currently performing as intended as far as actual motor control goes.
According to the manual for the RMI board, the jumper for Analog Output 3 is set to V OUT, but it has been set to C OUT. Also according to the manual:
"Analog output 3 is jumper-selected between voltage or current signals (refer to table 2.3). The default current range is 0 to 20mA. Further adjustments in current offset and range can be programmed. For example, for a range of 4 to 20mA on output 3:
r.008 (Offset) = +819 and r.009 (Gain) = 0.8
The data from the regulator to the analog outputs is normalized so that 4095 corresponds to positive full scale. Additional gain and offset calculation is done by the RMI board. For outputs 1 and 3, the drive will take the absolute value of the data. The value for output 2 may be signed (±4095)."
Currently analog output 3 from the RMI board is wired to a 1746-NI8 analog input card on a SLC 5/04 giving feedback on motor kW as 4-20mA. The inputs are scaled for PID, so 4-20mA = 0-16383, as I injected 12mA on the channel and was reading 8192. However, when we read the mA when the drive wasn't running (before changing any parameters), the analog output was reading something like 0.66mA. The as-found parameters were:
r.007 (Analog Output 3 Source) = 6 (Motor Power kW)
r.008 (Analog Output 3 Offset) = 0
r.009 (Analog Output 3 Gain) = 1.557
First we tried the recommended settings in the quoted section of the manual above, and changed r.008 to +819 and r.009 to 0.8. This brought the mA reading with the drive not running to around 2.7mA, but obviously (to me anyways) the reading should be around 4mA. I then tried changing r.009 to 4.000 (with r.008 still 819), as I figured this might give us a range of 3276-16383, but the PLC was showing 75% (16mA) on the analog input with the drive off. Lowering the gain to 1.000 and changing the offset to 3276 gave the same result. Thinking afterwards, I remembered that the channel is set to scaled for PID, so 3276 wouldn't give 4mA, but it also shouldn't be 16mA. I've sent a message to the guy onsite to try an offset of 0 with a gain of 4.000 to see if anything happens, but is anyone here familiar with the GV3000 and the RMI board?
EDIT #2: Also for reference, the drive and motor are 40HP (~30kW). The RMI board manual says the maximum scaling for Motor kW is H.000 (Motor NP Volts) x H.002 (Motor NP Amps) x 1.5 x 1.73 (V/Hz), which would be 460V x 52.0A x 1.5 x 1.73 = 62,072W or 62kW. Does this mean that we would under normal full load (30kW) only see around 12mA?
Working on a project that uses an old Reliance GV3000 on an agitator, with the optional Remote Meter Interface (RMI) board for additional I/O. The equipment was bought second-hand and everything had been previously working as intended as far as I know.
EDIT: We followed the recommended capacitor reforming procedure, and the drive is currently performing as intended as far as actual motor control goes.
According to the manual for the RMI board, the jumper for Analog Output 3 is set to V OUT, but it has been set to C OUT. Also according to the manual:
"Analog output 3 is jumper-selected between voltage or current signals (refer to table 2.3). The default current range is 0 to 20mA. Further adjustments in current offset and range can be programmed. For example, for a range of 4 to 20mA on output 3:
r.008 (Offset) = +819 and r.009 (Gain) = 0.8
The data from the regulator to the analog outputs is normalized so that 4095 corresponds to positive full scale. Additional gain and offset calculation is done by the RMI board. For outputs 1 and 3, the drive will take the absolute value of the data. The value for output 2 may be signed (±4095)."
Currently analog output 3 from the RMI board is wired to a 1746-NI8 analog input card on a SLC 5/04 giving feedback on motor kW as 4-20mA. The inputs are scaled for PID, so 4-20mA = 0-16383, as I injected 12mA on the channel and was reading 8192. However, when we read the mA when the drive wasn't running (before changing any parameters), the analog output was reading something like 0.66mA. The as-found parameters were:
r.007 (Analog Output 3 Source) = 6 (Motor Power kW)
r.008 (Analog Output 3 Offset) = 0
r.009 (Analog Output 3 Gain) = 1.557
First we tried the recommended settings in the quoted section of the manual above, and changed r.008 to +819 and r.009 to 0.8. This brought the mA reading with the drive not running to around 2.7mA, but obviously (to me anyways) the reading should be around 4mA. I then tried changing r.009 to 4.000 (with r.008 still 819), as I figured this might give us a range of 3276-16383, but the PLC was showing 75% (16mA) on the analog input with the drive off. Lowering the gain to 1.000 and changing the offset to 3276 gave the same result. Thinking afterwards, I remembered that the channel is set to scaled for PID, so 3276 wouldn't give 4mA, but it also shouldn't be 16mA. I've sent a message to the guy onsite to try an offset of 0 with a gain of 4.000 to see if anything happens, but is anyone here familiar with the GV3000 and the RMI board?
EDIT #2: Also for reference, the drive and motor are 40HP (~30kW). The RMI board manual says the maximum scaling for Motor kW is H.000 (Motor NP Volts) x H.002 (Motor NP Amps) x 1.5 x 1.73 (V/Hz), which would be 460V x 52.0A x 1.5 x 1.73 = 62,072W or 62kW. Does this mean that we would under normal full load (30kW) only see around 12mA?
Last edited: