Product Overview

The Honeywell 900H01-0202 is a relay output module with eight isolated channels.
Among these channels, four are Form C and the other four are Form A.
Each output uses an electromechanical relay as the primary switching device.
The module itself, however, does not include fuses for output protection.
For safety, install a fuse for each output at the field device instead.
Choose fuse ratings appropriate for your specific load and wire gauge.
Because of this design, the 900H01-0202 suits discrete control of motors, solenoids, and valves.

Technical Specifications

Output Channel Configuration

The Honeywell 900H01-0202 provides 4 Form A and 4 Form C outputs.
Form A outputs are normally open (NO) with a single contact.
In contrast, Form C outputs offer both normally open and normally closed contacts.
This mix of contact types provides flexibility for various application needs.
All eight channels are individually isolated from each other for safety.

Voltage and Current Ratings

The relay contacts handle 120/240 VAC or 30 VDC operating voltage.
For resistive loads, the current rating reaches 4A at 240VAC or 30VDC.
For incandescent lamp loads, however, the rating is 0.5A at 240VAC or 30VDC.
Maximum leakage current equals 1 mA at 350 VDC for isolation testing.
No de-rating applies for maximum outputs at maximum load conditions.
Similarly, no limit exists for maximum modules per rack in the system.

Response Times

OFF to ON response time reaches 11 ms maximum for reliable switching.
ON to OFF response time, on the other hand, reaches 8 ms maximum for quick de-energization.
These times exclude controller scan time and backplane transmission delays.
For this reason, total system response will be slightly longer than these values.

Expected Relay Life

Mechanical life reaches 5 x 10⁷ operations at 180 cycles per minute.
Electrical life reaches 10⁵ operations under rated resistive load conditions.
This electrical life applies specifically to resistive load switching applications.
For lamp loads or inductive loads, however, electrical life may be considerably shorter.

Galvanic Isolation

The 900H01-0202 provides isolation between individual relay output contacts.
It also provides isolation from relay output contacts to logic circuits.
This isolation effectively prevents electrical noise from affecting the control system.
Channel-to-channel isolation also allows mixing different voltage types safely on one module.

Fail Safe State Configuration

The module supports two fail safe state configuration options for flexibility.
First, Hold Last State maintains the last known output position after a fault.
Second, Failsafe State sets outputs to a predetermined safe condition immediately.
You can configure this behavior to match your specific safety requirements.

Status Indication

A green LED state indicator exists for each of the eight channels.
This LED turns on when the corresponding digital output becomes active.
Meanwhile, a green blinking status LED indicates active module scanning.
When this green LED blinks, the 900H01-0202 operates within normal parameters.
A red status LED, however, lights when module or channel diagnostics exist.
Because of these indicators, operators can quickly identify fault conditions visually.

Key Features

The Honeywell 900H01-0202 mixes Form A and Form C outputs conveniently.
Unlike fused modules, this unit requires external fusing at field devices.
For this reason, you can select fuses matched to your specific load types.
The electromechanical relay design provides true dry contact switching for compatibility.
Galvanic isolation also allows mixing of AC and DC loads on one module.
Moreover, no de-rating means you can use all eight channels at full capacity.

Installation Guidelines

Mount the Honeywell 900H01-0202 in a compatible 900 Series rack.
Ensure the module aligns correctly with the backplane connectors during insertion.
Secure the module firmly using the retaining screws at top and bottom.
For each output, install an appropriate fuse at the field device terminal.
Use fast-blow fuses for inductive loads; use slow-blow fuses for motor loads instead.
Do not exceed the 4A resistive load rating under any operating circumstances.
For DC inductive loads, use suppression diodes to extend relay life.
For AC inductive loads, use RC snubbers to reduce contact arcing.
After wiring, verify channel configuration in the control software application.
Finally, monitor the green blinking LED to confirm normal scanning operation.

Wiring Recommendations

Use copper cables with cross section of 0.5 to 1.5 mm² for all outputs.
Strip the wire insulation to 6-7 mm for proper terminal insertion.
For Form A outputs, connect the load between the common and NO terminal.
For Form C outputs, use NC for fail-safe operation or NO for normal operation.
Keep AC and DC wiring in separate cable ducts whenever possible.
Label each channel clearly according to your wiring diagram for reference.
Document the fuse rating used for each output channel carefully.
Use ferrule terminals on stranded wires for reliable and secure connections.

Load Compatibility Guide

For resistive loads such as heaters and resistors, use full 4A capacity.
For inductive loads like solenoids and relays, add suppression devices.
For lamp loads, derate to 0.5A due to high inrush current at startup.
For motor loads, use an external contactor or motor starter instead.
For DC loads, connect a freewheeling diode directly across the coil.
For AC loads, connect a varistor or RC snubber across the coil terminals.

Package Contents

• 1 x Honeywell 900H01-0202 relay output module

• 1 x Front access terminal block (18-pin)

• 1 x Module label sheet for channel identification

• 1 x Installation instruction document

• 1 x Relay contact suppression application note

Frequently Asked Questions (FAQ)

1. Why does the 900H01-0202 module not include built-in fuses?

The Honeywell 900H01-0202 expects external fusing at field devices. This approach lets you select fuse ratings for your specific load and wire gauge.

2. Can I mix AC and DC loads on the same module?

Yes, the 900H01-0202 provides galvanic isolation between all channels. As a result, you can connect 120V AC on one channel and 24V DC on another safely.

3. What is the difference between Form A and Form C outputs?

Form A provides a single normally open contact on the Honeywell 900H01-0202 . Form C, however, provides both normally open and normally closed contacts for flexibility.

4. How do I extend the electrical life of the relays?

Add suppression devices across your inductive loads for arc reduction. For DC loads, use diodes; for AC loads, use RC snubbers with the 900H01-0202 .

5. What happens to outputs when the module loses communication?

You configure the fail safe behavior during initial system setup. The Honeywell 900H01-0202 can either hold last state or go to a predetermined safe state.