What is a time delay relay and what industrial problems does it solve?

A time delay relay controls when a circuit is switched on or off, based on a precise programmable timer rather than an operator's manual action. It solves problems like: preventing motor overload during direct-on-line starting by adding a startup delay, controlling sequential machine operations (start conveyor A, then start conveyor B after 10 seconds), managing star-delta motor starting transitions, automating cyclic operations (pump on for 5 minutes, off for 10 minutes), and preventing rapid cycling of compressors or pumps.

What is the difference between the REV-201M, REV-120, and REV-114?

The REV-201M is a dual-channel relay with 7 operating modes — best when you need two independent timers in one unit or a star-delta motor starting sequence. The REV-120 is a compact single-channel relay with 10 operating modes including external contact triggered delays — best for simple, space-saving automation with analog knob adjustment. The REV-114 is the most advanced with 17 operating modes and a digital countdown display — best when critical timing accuracy is needed and operators must visually confirm the remaining delay time.

Can a time delay relay be used for star-delta motor starting?

Yes. The REV-201M's dual-channel architecture includes a dedicated star-delta starting algorithm. In star-delta starting, the motor initially connects in star configuration (reduced voltage and current), then transitions to delta configuration after a set time delay for full-power operation. The REV-201M's two output channels control the star contactor and the delta contactor respectively, with the transition time set by the T2 timer. This is one of the most common uses of the REV-201M in industrial motor control panels.

I need to control a pump that must run every 30 minutes for 5 minutes. Can these relays do that?

Yes. This is called a cyclic timer application and all three REV models support it. You set the 'OFF time' (pause between cycles) and the 'ON time' (working duration). The relay will continuously cycle the pump on and off automatically without any manual intervention. This is used in irrigation systems, cooling water circulation, chemical dosing, and wastewater treatment applications. The REV-201M and REV-114 give the broadest time range — from 0.1 seconds to 10 days per interval.

What does a '17-mode operation' relay like the REV-114 offer that simpler relays do not?

A 17-mode relay like the REV-114 can perform 17 different timing sequences from the same hardware unit. Beyond basic on-delay and off-delay, it includes: pulse generator mode, start-on-contact-close with stop on contact-open, flashing signal output, asymmetric cyclic operation, and more complex sequences used in safety interlocks and industrial PLC-supplementing applications. This means one REV-114 can replace 5 or more single-function timer relays, reducing panel complexity and stock cost.

The power in my area fluctuates between 160V and 270V. Will these relays still work correctly?

Yes. This is one of the standout features of the Novatek REV series. The REV-201M operates correctly across 150V to 300V AC. The REV-120 operates from 130V to 300V AC. These are exceptional ranges designed specifically for the variable grid conditions found in India and developing markets. Standard timer relays often malfunction, reset, or lose time when voltage dips, but the Novatek REV series maintains accurate timing through brownouts and surges.

How accurate is the timing on these microprocessor-based relays?

The REV series uses an internal microcontroller clock for timing, achieving accuracy of ±0.5% or better. This means a timer set to 60 seconds will be accurate to within 0.3 seconds. By contrast, traditional RC-circuit or mechanical timer relays are susceptible to temperature drift, component ageing, and voltage variation — typical accuracy of ±10–15%. For industrial applications where timing precision affects process quality or motor protection, the microprocessor-based REV series is far superior.

Can I use the REV-201M to add a startup delay to my submersible pump to prevent pressure surge?

Yes. Using the on-delay mode of the REV-201M, you can add a programmable delay (e.g., 5–30 seconds) between when power is applied and when the pump motor contactor closes. This is useful in pump station applications where direct-on-line starting causes water hammer (pressure surge) in the pipework. It is also used to sequence multiple pumps in a system so they do not all start simultaneously, avoiding current spikes that trip the main breaker.

What is the timing range available in the REV series?

All REV models cover a timing range from 0.1 seconds up to 10 days (864,000 seconds) in a single unit. This eliminates the need to stock different timers for short-duration operations (e.g., 2-second valve actuation) and long-duration applications (e.g., 12-hour irrigation cycle). You switch between time ranges using a front-panel selector, and fine-tune within the selected range using the adjustment knob or digital entry.

Which REV model would you recommend for a refrigeration panel where operators need to see the remaining defrost time?

The REV-114 is the ideal choice here. Its 7-segment digital display shows the real-time countdown in seconds/minutes/hours as the timer runs, allowing operators and maintenance staff to see exactly how much defrost time remains without opening the panel or using a stopwatch. This visibility is critical in food storage, cold chain logistics, and process cooling applications where defrost timing directly affects product quality.

Multifunction Time Delay Relays or Delay Timers (REV series)

Novatek Electro India’s line of multifunction timers—specifically the REV-201M, REV-120, and REV-114—are microprocessor-based devices designed for industrial automation. While they all perform timing functions, they differ in their channel density, user interface, and the complexity of their operating algorithms.

How They Work (Operational Principles)

All three models function by controlling the state of their output relay contacts based on a preset time delay and a selected logic “algorithm.”

REV-201M: The Dual-Channel Versatile Relay

Dual-Channel Logic: It contains two independent channels. You can use it in Independent Mode (acting as two separate timers) or Parallel Mode (one input triggers two outputs with different delays).
Adjustment: Uses four analog knobs (potentiometers) to set T1 (delay/pause) and T2 (work time) for each channel.
Algorithms: It typically features 7 operation modes, including On-delay, Pulse, Cyclic, and a specialized Star-Delta motor starting logic.

REV-120: The Compact Standard

Single-Channel Control: A slim, 18mm (1 DIN) module designed for space-saving.
Adjustment: Features two knobs—one for selecting the time range (0.1s to 10 days) and another for fine-tuning the specific delay.
Algorithms: Offers 10 operation modes. Unlike the 201M, it includes modes triggered by an external control contact (S-contact), such as Off-delay upon contact opening.

REV-114: The Digital Precision Relay

Digital Interface: Unlike the others, the REV-114 features a 7-segment digital display and push-buttons for programming.
Feedback: The display shows the remaining time countdown in real-time, which is critical for operators to see exactly when a process will trigger.
Algorithms: This is the most “powerful” of the three, offering 17 operation modes, including complex start/stop and pulse generator sequences.

Key Advantages

Microprocessor Control: Unlike traditional thermal or RC-circuit timers, these use microcontrollers for high repeat accuracy (±0.5% or better).
Broad Timing Range: They cover everything from 0.1 seconds to 10 days in a single unit, eliminating the need to stock different timers for seconds vs. hours.
High Load Resilience: They are designed to work in harsh electrical environments, with a wide operating voltage tolerance (e.g., maintaining capability from 130V to 300V for the REV-120).
Compact DIN-Rail Mounting: All models are designed to snap onto standard 35mm rails, with the REV-114 and REV-120 taking up only 18mm of space.
Multi-Functionality: One Novatek relay can often replace five different single-function timers (On-delay, Off-delay, Cyclic, etc.), reducing inventory costs.

Comparison Table: Novatek vs. Others

Feature	Novatek REV Series	Standard “Others” (Analog/Legacy)
Logic	Microprocessor-based (Digital logic)	Often RC-circuit (Analog components)
Modes	Multi-algorithm (up to 17 modes)	Usually Single-function (On-delay only)
Accuracy	High (Internal clock-based)	Moderate (Prone to temperature/drift)
Display	LED Indicators or Digital Countdown	Usually just a power/trip LED
Time Range	Universal (0.1s to 10 days)	Fixed (e.g., 0–30s or 0–10 min)

Summary of Differences

REV-201M is best when you need two timers in one or a Star-Delta starter.
REV-120 is the go-to for simple, space-saving automation with analog knob adjustments.
REV-114 is the choice for critical timing where a digital readout and many specialized modes are required.

Power Supply & Voltage Tolerances – The standout feature of Novatek’s power circuit is its wide operating window. While most timers fail or reset if the voltage drops slightly, these units are designed to stay functional during significant brownouts or surges.

Model	Rated AC Voltage	Voltage Range (Stability)	DC Power Support
REV-201M	220–240V AC	150V – 300V	24V DC (±10%)
REV-120	230–240V AC	130V – 300V
REV-114	230–240V AC	185V – 280V