Diagnosing IC693MDL916 Relay Outputs Before Module Replacement

The General Electric IC693MDL916 is a Series 90-30 relay output module with 16 isolated Form A contacts. A dark load does not prove the module has failed. Check the command, terminal block and switched circuit separately.

Confirm the output command

Use the channel LED and controller logic together. An LED that never turns on points to logic, addressing or controller state. An active LED with no field voltage moves the check to the terminal block, contact and load circuit.

Check the removable terminal block

The module uses a 36-position removable terminal block. GE lists box-style IC694TBB032/TBB132 and spring-style IC694TBS032/TBS132 blocks.

Confirm the block is fully seated and locked. Then check the assigned output and return terminals against the wiring drawing. Do not move conductors by physical position alone.

Measure on both sides of the relay contact

IC693MDL916 contacts switch an external supply. The module does not create field power for the load.

• Measure the external supply at the terminal block.
• Command the output on and measure across the contact.
• Measure voltage at the load under current.
• Check the return path and protective device.

A correct command with no external supply is a field-power fault. Supply present on one side only, with the LED on, indicates an open contact path or terminal problem.

Check the load against the contact rating

The retained module data lists 4 A maximum per point for 5–30 VDC and 5–250 VAC resistive loads. At 125 VDC, the listed maximum is 200 mA. The minimum load is 10 mA.

Do not apply the 4 A figure to every voltage. Include contactor-coil or lamp inrush when comparing the load with the rating.

Check switching rate and timing

The listed maximum switching rate is 20 cycles per minute. The nominal on/off response is 10 ms, excluding contact bounce.

Rapid logic chatter can exceed the mechanical relay duty even when steady-state current is acceptable. Trend the command bit before replacing the module.

Replacement record

• Record the exact IC693MDL916 catalog number.
• Photograph the 36-terminal block before removal.
• Record external supply voltage and load current.
• Check the output command and channel LED.
• Verify the terminal block type and lock.
• Test the contact path under load.

See the IC693MDL916 product page for the current product record.

Source

Electrical limits and module support were checked against the Emerson PACSystems RX3i System Manual, which includes IC693MDL916 support.