Honeywell DC120L10001000 Limit Controller

Nom et prénom: Honeywell UDC120L10001000, a UDC1200 Micro-Pro 1/16 DEPUIS Limit Controller. It is not a conventional PID temperature controller. It is designed for safety over-limit protection with latching alarm function.

1. Décodage du code modèle: DC120L 10001000

DC120L: UDC1200 series Limit Controller (differentiated from DC1201/1202 conventional PID controllers)

1: Main Output 1, SPDT Relay

0: No auxiliary output

0: Aucune communication

1: Universal Power Supply 90–264VAC (50/60Hz)

0: No second output

0: No optional extras

0: No additional alarm

2. Spécifications de base

3. Fonctions clés (Main Differences Between Limit Controller & Normal PID Controller)
4. Over-limit Latching Protection: When the measured value exceeds the set limit value, the relay actuates and latches. Manual reset is required for recovery. Applied for over-temperature safety cut-off of ovens, furnaces and heat treatment equipment (safety temperature limiter).
5. Universal sensor input supporting thermocouples, RTDs and analog signals.
6. Sensor break detection: TC/RTD break triggers alarm output.
7. Password-protected parameters to prevent unauthorized modification of limit values on site.
8. No PID automatic regulation. Only upper / lower limit safety protection (cannot be used for continuous temperature regulation).
9. Scénarios d'application typiques

Over-temperature safety protection loops for industrial ovens, heat treatment furnaces, aging test chambers, environmental chambers, boiler auxiliaries, plastic extruders and food baking equipment. Often used together with conventional PID temperature controllers (PID controller handles regulation; DC120L serves as independent safety temperature limiting).

5. Installation & Directives de câblage
6. Panel snap-in mounting, max panel thickness 6mm; keep heat dissipation gaps front and rear.
7. Relay contacts are dry contacts with external load power supply. Do NOT connect high voltage to instrument internal terminals.
8. Route sensor cables separately away from power cables to reduce interference.
9. Unlock via password before commissioning to modify temperature limits. Manual key reset is required after latch activation.
10. Alternative / Optional Models
11. Même série: Other DC120L suffix versions (DC120L10011000 with RS485 communication)
12. Alternatives nationales: Yudian AI series limit controllers, Hongrun NHR-1100 (fonctions similaires, latch logic needs verification)
13. Legacy Honeywell replacement: DC1000 series limit type (gradually phased out)
14. Dépannage courant

Sensor error displayed: Check TC/RTD polarity, wire breakage and cold junction compensation.

No latch after over-limit: Confirm function mode is set to Limit latch mode instead of ordinary alarm mode.

Relay fails to actuate: Verify contact load rating, terminal wiring and instrument power supply.

Parameters cannot be modified: Instrument password locked, enter unlock password.

8. Référence du code SH (For Foreign Trade)

9032890090 Other automatic regulating or controlling instruments and apparatus

Tableau de comparaison: Honeywell DC120L (UDC120L10001000) vs UDC1202 PID Temperature Controller

Selection Recommendation Summary

1. Equipment requiring safety redundancy, hard over-temperature cut-off and fault latching: Dual-instrument scheme: UDC1202 (main temperature control) + DC120L (independent temperature limit) (widely used for heat treatment, ovens and aging chambers)
2. Only conventional constant temperature control required with no mandatory safety latch requirement: Select UDC1202 directly
3. Only over-temperature protection required without automatic temperature control: Select DC120L alone

Honeywell DC120L10001000 (UDC120L Limit Controller) Document technique

Nom complet du produit: Honeywell UDC1200 Micro-Pro DC120L Limit Controller

Document Type: Datasheet / Technical Specification Manual (English Engineering Version)

Modèle applicable: DC120L10001000 (Sortie relais, No Communication, 90~264VAC Power Supply)

Positionnement du produit: Independent safety limit instrument, no PID regulation, over-limit latching trip, applied for equipment over-temperature safety protection

1. Model Code Definition DC120L 1 0 0 1 0 0 0

2. Électrique & Spécifications mécaniques

Universal Input Types (Supported Sensors)

Thermocouple: K, J., R., S, B, E, N, T

RDT: Pt100 (DIN43760 0.00385)

Linear Analog: 4~20mA, 0~20mA, 0~10 V, 1~5V

3. Description de la fonction principale
4. Limit Latch Protection【Core Feature】

When measured PV exceeds setpoint SP, relay actuates and latches in trip state. No automatic recovery upon temperature drop; manual key reset required. Meets hard cut-off safety requirements for ovens and heat treatment furnaces.

Configurable for high limit or low limit mode.

2. Sensor Break Diagnosis

Breakage of thermocouple, RTD or 4-20mA signal triggers limit output action to prevent runaway caused by sensor failure.

3. Parameter Password Lock

Parameter menu protected by password to prevent unauthorized modification of safety limit values. Password unlock required to edit SP, input type and latch mode.

4. Dual 4-digit LED Display

Upper screen: PV real-time measured value; Lower screen: SP set limit value. Status LED indicates output/alarm/latch status.

5. No PID Automatic Control

This instrument has no PID regulation function and cannot act as primary temperature controller. It serves only for independent safety over-limit protection, forming dual-loop safety temperature control system when paired with UDC1202 PID controller.

4. Définition du câblage des bornes (DC120L Basic Version)

Remarque importante: Relay contacts are passive dry contacts. Do NOT connect load power supply to instrument internal power terminals.

1. L, N: Instrument power supply, 90~264VAC
2. Sensor input terminals: Thermocouple / Pt100 / 4-20mA
3. Main output relay: COM commun, NON normalement ouvert, NC normalement fermé

Typical wiring: Use NC normally closed contact. Contact closes under normal temperature; opens upon over-temperature latch to cut heating circuit.

Wiring Recommendation: Use shielded twisted pair for sensor cables, routed separately from power cables to reduce interference.

5. Spécifications d'installation
6. Panel snap mounting, max panel thickness 6mm; reserve heat dissipation gap for side-by-side multi-unit installation.
7. Température ambiante de fonctionnement: 0~50℃; ambient humidity: 20~80% HR, no condensation and corrosive gas.
8. Keep away from high-power contactors, frequency converters and strong electromagnetic interference sources.
9. Mise à la terre: Instrument chassis grounding; single-end grounding for shield layer.
10. Opération & Configuration Overview

6.1 Enter Parameter Menu

Press 【UP】+【SETUP】 simultaneously, enter password (common password:10/20) to unlock and enter configuration mode.

6.2 Key Configurable Parameters

Input type code (sensor model selection)

Full scale upper/lower range

Limit SP (safety protection threshold)

Limit mode: high limit latch / low limit latch

Latch enable/disable

Action logic for sensor break

Password setting & parameter locking

6.3 Latch Reset

After over-limit latch trip, perform manual reset via keys on operator interface to restore relay contacts to normal state.

7. Scénarios d'application typiques

Independent over-temperature safety protection loops for industrial ovens, hot air furnaces, heat treatment furnaces, aging test chambers, environmental chambers, plastic extruders and food baking equipment.

Standard scheme: UDC1202 (PID main temperature control) + DC120L (independent temperature limit protection) dual-instrument redundant control complying with equipment safety standards.

8. Tableau de diagnostic des défauts

9. Alternative Model Information

Same Honeywell series: DC120L10011000 (version with RS485 communication)

Alternatives nationales: Yudian AI series limit controllers, Hongrun NHR-1100 (latch logic requires verification)

Remplacement hérité: DC1000 series limit controller (abandonné)

10. HS Code for Foreign Trade

Code SH: 9032890090 Other automatic regulating or controlling instruments and apparatus

11. Notes de sécurité
12. This instrument is a safety limit protection device, cannot be used alone for process temperature control.
13. External contactor is recommended for safety circuit. Relay contact capacity is limited and cannot directly drive high-power heating loads.
14. Periodic over-temperature test on safety circuit is required to verify latch trip function.
15. Disconnect power before instrument disassembly and wiring, comply with local electrical safety regulations.